Chem II Final
When the concentration of hydronium and hydroxide is equal what does that mean?
neutral
What is the principle factor in determining nucleus stability?
neutron to proton ratio
HNO3
nitric acid
Changing concentration does what to the value of the K?
nothing
What is a reversible process?
one that can go back and forth between states along the same path
What is an ideal solution?
one that obeys Raoult's law
The equation for osmotic pressure is
pi=MRT
What is the osmotic pressure equation?
pi=MRT
Below belt of stability
positron emission or electron capture
What are tracers?
radioactive isotopes that can be followed through the steps of a chemical reaction or industrial process
What is the slowest step in a reaction mechanism?
rate determining step
What is the rate of radioactive decay?
rate of decay at time t= kN k=first order rate constant N=number of radioactive live nuclei present at time t
What does k equal?
rate/concentration
Write the rate law for the following elementary reaction: F (g) + H2 (g) ---> HF (g) + H (g)
rate=k[F][H2]
H2(g) + 2I (g) ---> HI (g)
rate=k[H2][I]^2
Write the rate law for the following elementary reaction H2(g) + 2I(g) ---> 2HI (g)
rate=k[H2][I]^2
Titration of weak acid and strong base
initially- weak acid in beaker; ICE table or pH=-log*square root*(Ka x M1) before equivalence point- buffer in the beaker; pH= pKa +log(base)/(acid) 1/2 equivalence point- equal amounts of weak acid and conjugate base in beaker; pH=pKa equivalence point- weak base in the beaker; ICE table or pOH=-log*square root*(Kb x M) after equivalence point- strong base and weak conjugate base in the beaker; pOH=-log(strong base)
What is the initial rate?
instantaneous rate at t=0
What are the intermolecular forces that exist between solute and solvent when an ionic compound dissolves in water?
ion-dipole
What is rate constant?
is a reflection of the probability that a reaction will occur relates the rate of the reaction to the concentration of reactants. k
A chemist mixes 63 g of diethyl ether with 71 g of methanol and 11 g of acetone. Calculate percent by mass of each compound of this solution.
methanol=49% acetone=7.6%
What does hypertonic mean?
more solute, less water
What is the half life equation?
t1/2 = 0.693/k
What is rate of reaction?
the change in concentration of a substance per unit time
What is mass defect?
the difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons, expressed in kg
What is boiling point elevation?
the difference in temperature between the boiling point of a solution and the boiling point of the pure solvent
What is freezing point depression?
the difference in temperature between the freezing point of a solution and the freezing point of the pure solvent
What is an anode?
the electrode at which oxidation occurs
What is a cathode?
the electrode at which reduction occurs
What is radioactivity?
the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei
What is nuclear transmutation?
the induced conversion of the nucleus of one element into the nucleus of another
What is a critical mass?
the minimum amount of nuclide that provides the number of neutrons needed to sustain a chain reaction
What is a parent nuclide?
the nucleus that is undergoing radioactive decay
What is the daughter nuclide?
the nuclides produced by the decay of the parent nuclides
What is a molecularity?
the number of molecules that need to collide simultaneously for a reaction to occur
What is molar solubility?
the number of moles of solute that will dissolve in a liter of solution
Most probable state is
the one with the largest number of possible arrangements
What is the equivalence point?
the point at which neutralization occurs
What is the endpoint?
the point at which the indicator changes color
What is instantaneous rate?
the slope of a line tangent to the curve at any point
What is the rate determining step?
the slowest step in a reaction
What is a conjugate acid?
the species that is formed when a Bronsted-Lowry base gains a proton
What is a conjugate base?
the species that remains after a Bronsted-Lowry acid has given up a proton
What is chemical kinetics?
the study of reaction rates
If both components are volatile the vapor pressure of the solution is
the sum of the individual partial pressures exerted by the solution componenets
What is half life?
the time taken for the radioactivity of a specified isotope to fall to half its original value
What is corrosion?
the unwanted oxidation of metals to produce a metal oxide
What is a trimolecular?
three reactant molecules
What is a concentration cell?
type of galvanic cell in which the only difference is concentrations
What are the four colligative properties?
vapor pressure lowering, boiling point elevation, freezing point depression, osmotic pressure
What is the boiling point?
vapor pressure=external pressure
What does hydrophilic mean?
water loving
When a nonvolatile solute is dissolved in liquid
what happens?,The vapor pressure exert by the liquid decreases?
Use the quadratic formula to solve for x 5x^2 + x - 1=0
x=0.36 or -0.56
Use the quadratic formula to solve for x 6x^2-9x=-1
x=1.38 or x=0.12
Solve 5y^2-60=0 where y is a real number. Round your answer to the nearest hundredth. If there is more than 1 solution, separate them with commas. If there is no solution, say no solution
y=3.46 or -3.46
What is the equation that related Gibbs free energy to reduction potential?
ΔG=−nFEcell or ΔG∘=−nFE∘cel
What is the standard free energy of reaction equation?
ΔG∘(rxn)=ΣΔG∘f(products)−ΣΔG∘f(reactants)
What is the freezing point depression equation?
ΔTf = Kfm
What is Gibbs free energy equation?
∆G = ∆H - T∆S
When the solute is liquid and the solvent is solid what is the state of the resulting solution?
solid
H2SO4
sulfuric acid
A solution with more solute than it would normally be able to hold and can crystallize quickly
supersaturated
What is percent by mass (or percent by weight)?
(mass of solute/mass of solution) * 100%
How can rate be expressed?
-(delta[A]/delta t) or delta[B]/delta t
Using the thermodynamic information provided, calculate the standard reaction free energy of the following chemical reaction: 2CH3OH (g) + 3O2 (g) -----> 2CO2 (g) + 4H2O (g) Round to 0 decimal places. CH3OH (g) = -162.3 kJ/mol O2 (g) = 0 kJ/mol CO2 (g) = -394.4 kJ/mol H2O (g) = -228.6 kJ/mol
-13.79 kJ
Calculate Delta G for 2CH3OH (l) + 3O2 (g) ---> 2CO2 (g) + 4H2O (g) using Delta G standard of formation valules
-1370.0 kJ
4FeCl3 (s) + 3O2 (g) ----> 6Cl2 (g) + 2Fe2O3 (s) Delta H=-50 kJ Delta G= 0 kJ Calculate Delta S and determine spontaneity
-139 J/K and the reaction is at equilibrium
Calculate Delta G at 298 K for the reaction: N2 (g) + 3H2 (g) ---> 2NH3 (g) if the pressures of each gas are: 0.50 atm N2, 0.75 atm H2 and 2.0 atm NH3
-25.5 kJ/mol
Calculate ΔG˚ for the reaction of the following voltaic cell: Al (s) + Cr^3+ (aq) ---> Al^3+ (aq) + Cr(s)
-269 kJ
The equilibrium constant Kp for the reaction N2O4 (g) ----> 2NO2 (g) is 0.113 at 298 K which corresponds to a free-energy change of 5.4 kJ/mol. In a certain experiment, the initial pressures are PN2O4=0.453 atm and PNO2=0.122 atm. Calculate Delta G for the reaction at these pressures and predict the direction in which the reaction will proceed spontaneously to establish equilibrium
-3.1 kJ/mol and proceeds spontaneously in the forward reaction
Calculate Delta S standard of reaction for the synthesis of urea reaction: 2NH3 (g) + CO2 (g) ---> NH2CONH2 (aq) + H2O (l) using standard S values
-355.9 J/K
A chemist fills a reaction vessel with 5.01 atm N2 gas, 4.24 atm H2 gas and 9.15 atm NH3 gas at a temperature of 25 degrees C. Under these conditions calculate reaction free energy delta G for the following reaction N2 (g) + 3H2 (g) ---> 2NH3 (g) Round to nearest kJ
-37 kJ
For a certain chemical reaction, the equilibrium constant K=3.5 * 10^6 at 30.0 degrees C. Calculate standard Gibbs free energy of reaction. Round to 2 sig figs
-38 kJ
P4 (s) + 20HF (g) ---> 4PF5 (g) + 10H2 (g) Delta H=-1005 kJ Delta S=-2772 J/K Calculate Delta G and determine spontaneity
-9 kJ and spontaneous
What does pH equal?
-log[H+] or -log[H3O^+]
What is pOH?
-log[OH-]
If the pH is 2.19, what is the hydronium concentration?
0.0065 M
Steam reforming methane (CH4) produces "synthesis gas" a mix of carbon monoxide and hydrogen gas, which is the starting point for many important industrial chemical syntheses. An industrial chemist studying this reaction fills a 1.5 L flask with 1.8 atm of methane gas and 2.3 atm of water vapor, and when the mix has come to equilibrium measures the partial pressure of carbon monoxide gas to be 0.18 atm. Calculate the pressure equilibrium constant for the steam reforming of methane at the final temperature of the mixture. Round to 2 sig figs
0.0083
At a certain temperature this reaction follows second order kinetics with a rate constant of 223 M^-1 * s^-1 2H3PO4 (aq) ----> P2O5 (aq) + 3H2O (aq) Suppose a vessel contains H3PO4 at a concentration of 0.120 M. Calculate the concentration of H3PO4 in the vessels 0.250 seconds later. You may assume no other reaction is important. Round to 2 sig figs
0.016 M
Suppose a 250 mL flask is filled with 1.1 mol of O2 and 0.30 mol of NO. The following reaction becomes possible: N2 (g) + O2 (g) ----> 2NO (g) The equilibrium constant K for this reaction is 9.64 at the temperature of the flask. Calculate equilibrium molarity of N2. Round to two decimal places
0.03 M
Determine concentration of a solution of ammonium chloride that has a pH of 5.37 at 25 degrees C
0.032 M
Calculate solubility for Ag2CO3 in water at 25 degrees C. Ksp=8.46 * 10^-12. Round to 2 sig figs
0.035
An aqueous solution at 25 degrees C has a pOH of 13.95. Calculate pH
0.05
5.8 * 10^-6 kg/mol*dL = ? g/mol*L
0.058
A solution dissolves 3.8 g of sucrose (C12H22O11) in 125 mL of a solvent with a density of 0.91 g/mL. The student notices that the volume of the solvent does not change when the sucrose dissolves in it. Calculate molality and molarity of the solution
0.098 m and 0.089 M
The reform reaction between steam and gaseous methane (CH4) produces "synthesis gas " a mixture of carbon monoxide and dihydrogen gas. Synthesis gas is one of the most widely used industrial chemicals, and is the major industrial source of hydrogen. Suppose a chemical engineer studying a new catalyst for the reform reaction finds that 707m L/s of methane are consumed when the reaction is run at 167 degrees C and the methane is supplied at 0.91 atm. Calculate the rate at which dihydrogen is produced give answer in kg/s
0.11 kg/s
The equilibrium constant Kc for this reaction: N2O4 (g) -------><----- 2NO2 (g) is 4.63*10^-3 at 25 degrees C. What is the value of Kp at this temperature
0.113
Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. An industrial chemist styling the reaction fills a 50.0 L tank with 4.8 mol sulfur dioxide gas and 22 mol of oxygen gas, and when the mixture has come to equilibrium the amount of sulfur trioxide gas is 0.96 mol. Calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mix. Round to 2 sig figs.
0.15
At 25 degrees C the Henry's Law constant for sulfur hexafluoride (SF6) gas in water is 2.4 * 10^-4 M/atm. Calculate the mass in grams of SF6 gas that can be dissolved in 1275 mL of water at 25.0 degrees C and a SF6 partial pressure at 3.80 atm
0.17 g
Suppose a 500 mL flask is filled with 0.50 mol of NO3 and 0.70 mol NO. The following reaction becomes possible: NO3 (g) + NO (g) ----> 2NO2 (g) The equilibrium constant K is 8.17 at the temperature in the flask. Calculate the equilibrium molarity of NO3. Round to two decimal places
0.32 M
How much HCl must be added to a L of buffer that is 1.5 M in acetic acid and 0.75 M in sodium acetate to result in buffer pH of 4.10?
0.33 mol
A student dissolves 19 g of benzoic acid (C7H6O2) in 450 mL of solvent with density 1.19 g/mL. The student notices that the volume of the solvent does not change when the benzoic acid dissolves in it. Calculate molarity and molality of the solution
0.35 M and 0.29 m
Hydrogen 3 is radioactive and has a half life of 12.3 years. How much of a 4.30 mg sample would be left after 44.1 years? Round to 2 sig figs
0.36 mg
At a certain temperature this reaction follows second order kinetics with a rate constant of 19.3 M^-1 * s^-1. 2NH3 (g) ----> N2 (g) + 3H2 (g) Suppose a vessel contains NH3 at a concentration of 0.500 M. Calculate how long it takes for the concentration of NH3 to decrease to 0.105 M. You may assume no other reaction is important. Round to 2 sig figs
0.39 s
In the Haber reaction patented by German chemist Fritz in 1908, dinitrogen gas combines with dihydrogen gas to produce gaseous ammonia. This reaction ice now the first step taken to make most of the world's fertilizers. Suppose a chemical engineer studying a new catalyst for the Haber reaction finds that 495 L per second of dinitorgen are consumed when the reaction is run at 174 degrees C and the dinitrogen is supplies at 0.95 atm. Calculate the rate at which ammonia is being produced. Give answer in kg/s
0.44 kg/s
5.6 * 10^-4 g/cm^3 = ? kg/m^3
0.56
A solution is made of mixing 45 g of benzene (C6H6) and 41 g of heptane (C7H16). Calculate mole fraction of benzene in this solution
0.58
Suppose a 500 mL flask is filed with 1.9 mol of CHCl3, 1.0 mol of HCl and 0.80 mol CCl3. The following reaction becomes possible: Cl2 (g) + CHCl3 (g) -----> HCl (g) + CCl4 (g) The equilibrium constant K is 0.683. Calculate equilibrium molarity of Cl2
0.58 M
Lead (II) nitrate is added slowly to a solution that is 0.020 M in Cl^- ions. Calculate the concentration of Pb^2+ ions (in M) required to initiate precipitation of PbCl2 (Ksp=2.4 * 10^-4)
0.60 M
How do you calculate half life?
0.693/k
A certain substance X condenses at a temp of 130.1 degrees C. But if 850 g sample of X is prepared with 93.0 g of Urea ((NH2)2CO) dissolved in it is found to have a condensation point of 131.6 degrees C instead. Calculate molal boiling point constant Kb, of X
0.82 degrees C*kg/mol
A chemist dissolves 435 mg of pure HCl in enough water to make 80 mL of solution. Calculate pH
0.83
Suppose a 500 mL flask is filled with 0.80 mol H2 and 0.60 mol of HI. The following reaction become possible: H2 (g) + I2 (g) ----> 2HI (g) the equilibrium constant K for this reaction is 2.24 at the temperature of the flask. Calculate equilibrium molarity of HI. Round to 2 decimal places
0.84 M
0.93 mol/L * 0.90 L
0.84 mol
consider a galvanic cell that uses the reaction Zn (s) + 2H^+ (aq) ---> Zn^2+ (aq) + H2(g) Calculate the cell potential at 25 degrees C when [H+]=1.0 M [Zn^2+]=0.0010 M and [H2]=0.10 M
0.88 V
Suppose a 500 mL flask is filled with 1.9 mol of CO, 1.6 mol H2O and 0.80 mol H2. The following reaction is possible: CO (g) + H2O (g) -----> CO2 (g) + H2 (g) The equilibrium constant K for this reaction is 6.52 at the temperature of the flask. Calculate the equilibrium of H2O. Round to two decimal places
0.91 M
Refer to the reaction 2A--->B For which k=7.5*10^-3 s^-1 at 110 degrees C. With a starting concentration of [A]=2.25 M what will [A] be after 2.0 min?
0.97 M
What is the symbol for a positron?
0/+1 e or 0/+1 B
Suppose a beryllium 10 nuclide decays into a boron 10 nuclide by emitting an electron. Complete the nuclear chemical equation below so that it describes this nuclear reaction 10/3 Be --->
0/-1 e + 10/5 B
What is the symbol for an electron?
0/-1 e or 0/-1 B
1. Delta H standard < T delta S standard 2. K < 1 3. Delta G standard > 0 4. ln K < 0 Which statement is false, if any?
1
1. Delta S standard > delta H standard/T 2. ln K < 0 3. K < 1 4. Delta G standard > 0 Which statement is false if any?
1
1. K=0 2. ln K = 0 3. Delta G standard = 0 4. Delta H standard = T delta S standard Which statement is false if any?
1
1. ln K = 1 2. Delta H standard = T delta S standard 3. K = 1 4. Delta G = 0 Which statement is false, if any?
1
Log term in Henderson Hasselbalch equation can only have values between
1 and -1
what does 1 joule =
1 kg * m^2/s^2
What is unimolecular?
1 reactant molecule
What are the three outcomes if you combine stoichiometric amounts of reactants
1) The reaction will essentially go to completion and the equilibrium will consist predominantly of products 2) It will not occur to any significant degree and the equilibrium mixture will consist predominantly of reactants 3) It will proceed to a significant degree, but won't go to completion and the equilibrium mixture will contain comparable amounts of reactants and products
When 373 mg of a certain molecular compound X is dissolved in 75.0 g of dibenzyl ether the freezing point of the solution is measured to be 1.5 degrees C. Calculate molar mass of X
1*10^2 g/mol
What are the three types of titrations?
1. Ones involving a strong acid and strong base 2. Ones involving a weak acid and a strong base 3. Ones involving a strong acid and a weak base
What are the two categories of oxyacid?
1. Ones that have central atoms and are from the same group on the periodic table and oxidation number. Within this group, strength increases with increasing electronegativity of central atom 2. Ones that have the same central atom, but different numbers of oxygen molecules within this group strength increases with increasing oxygens
What are the stability rules?
1. There are more stable nuclei containing 2,8,20,50,82 or 126 protons or neutrons 2. There are many more stable nuclei with even numbers of both protons and neutrons 3. All isotopes with atomic number higher than 83 are radioactive 4. All isotopes of technetium (Z=43) and promethium (Z=61) are radioactive
What are the steps of the solution process?
1. solvent particles move apart 2. solute separates into small molecules or ions 3. solvent and solute particles integrate
The concentration of hydronium ions in stomach acid is 0.10 M. Calculate the concentration of hydroxide ions in stomach acid at 25 degrees C
1.0 * 10^-13 M
A certain first order reaction has an activation energy of 83 kJ/mol. If the rate constant for this reaction is 2.1*10^-2 s^-1 at 150 degrees C what is the rate constant at 300 degrees C?
1.0*10^1 s^-1
Use the data in the following table to determine activation energy T(K). k(s^-1) 625. 1.1*10^-4 635. 1.5*10^-4 645. 2.0*10^-4 What is the value of k at 655 K?
1.0*10^2 kJ/mol, 2.7*10^-4/s
Kc=1.00*10^-4 at some temperature, 2.00 PCl5 is reacted in a 2.0 L vessel. Calculate the equilibrium mixture concentration PCl5----> PCl3 + Cl2
1.00 * 10^-2
An electrochemical cell is constructed for the purpose of determining the Ksp of CuCl at 25 degrees C. One half cell consists of a copper electrode in a 1.00 M solution of CuNO3. The other half cell consists of a copper electrode in a saturated solution of CuCl. The measured cell potential is 0.175 V. Determine the concentration of Copper (I) ion in the saturated solution and the value of Ksp for CuCl
1.11 * 10^-3 M and 1.2 * 10^-6
At a certain temperature this reaction follows first order kinetics with a rate constant of 1.84 s^-1. 2NH3 (g) ---> N2 (g) + 3H2 (g) Suppose a vessel contains NH3 at a concentration of 0.570 M. Calculate how long it takes for the concentration of NH3 to decrease to 11.0% of its initial value. You may assume no other reaction is important. Round to 2 sig figs
1.2 s
An electrochemical cell is constructed for the purpose of determining the Ksp of AgCN at 25 degrees C. One half cell consists of a silver electrode in a 1.00 M solution of silver nitrate. The other half cell consists of a silver electrode in a saturated solution of silver cyanide. The cell potential is measured and found to be 0.470 V. Determine the concentration of silver ion in the saturated silver cyanide solution and the volume of Ksp for AgCN
1.3 * 10^-16
If the pH is 4.89, what is the hydronium concentration?
1.3 * 10^-5 M
A solution is prepared at 25 degrees C that is initially 0.12 M in CH3NH2, a weak base Kb=4.4 * 10^-4, and 0.90 M in CH3NH3Cl. Calculate pH of solution to 2 decimal places
10.72
What is the pH of a 0.040 M ammonia solution at 25 degrees C?
10.93
Camphor C10H6O, melts at 179.8 degrees C and has Kf= 40.0 degrees C/m. When 0.186 g of an organic substance of unknown molar mass is dissolved in 22.01 g of camphor, the freezing point of the solution is found to be 176.7 degrees C. What is the molar mass of the solute?,
109 g/mol
What does the concentration of hydronium ions equal?
10^-pH
What does the concentration of hydroxide ions equal?
10^-pOH
What is the pH of a 0.20 solution of ammonia?
11.28
Given that the parent nuclide is 11/6 C and the decay mode is position emission what is the daughter nuclide?
11/5 B
The molal boiling point elevation constant Kb=1.08 degrees C * kg/mol for a certain substance X. When 50.72 g of urea are dissolved in 500 g of X. Calculate boiling point of pure X. The solution boils at 115.1 degrees C
113.3 degrees C
What is the pH of a 7.2 * 10^-3 M solution of Ba(OH)2?
12.16
A chemist dissolves 884 mg of pure barium hydroxide in enough water to make 190 mL of solution. Calculate pH
12.731
13.70 g -0.8 g
12.9 g
A chemist dissolves 712 mg of pure sodium hydroxide enough water to make up 170 mL of solution. Calculate pH
13.020
The reaction 2A--->B is second order in A with a rate constant of 32.0 M^-1 * s^-1 at 25 degrees C. (a) Starting with [A]0=0.0075 M how long will it take for the concentration to drop to 0.0018 M? (b) Calculate the half life of the reaction for [A]0=0.0075 M and for [A]0=0.0025 M
13.2 s, 42 s, 13 s
717.71 m / 51.72 s
13.88 m/s
Given that the decay mode is proton emission and the daughter nuclide is 13/6 C. What is the parent nuclide?
13/7 N
Suppose the amount of a certain radioactive substance in a sample decays from 4.70 mg to 2.00 mg over a period of 17.1 days. Calculate half life of the substance round to 2 sig figs
14 days
According to table 18.4 a reaction will be spontaneous at high temperatures if both ∆H and ∆S are positive. For a reaction in which ∆H=199.5 kJ/mol and ∆S=476 J/K * mol determine temperature in Celsius above which reaction is spontaneous
146 degrees C
Given that the parent nuclide is 150/64 Gd and that the decay mode is alpha emission what is the daughter nuclide?
146/62 Sm
Given that the decay mode is alpha emission and the daughter nuclide is 146/62 Sm what is the parent nuclide?
150/64 Gd
Suppose the amount of a certain radioactive substance in a sample decays from 1.10 mg to 900 micrograms over a period of 4.79 years. Calculate half life of the substance to 2 sig figs
17 years
An electric current transports 510 µC of charge in 30.0 seconds. Calculate size of electric current
17.0 µA
The fluorine 17 nuclide radioactively decays by electron capture. Write a balanced nuclear chemical equation that describes this process
17/9 F + 0/-1 e ---> 17/8 O + 0/0 gamma
The tungsten 180 nuclide radioactively decays by alpha emission. Write a balanced nuclear equation that describes this process
180/74 W ---> 176/72 Hf + 4/2 He
Tin 129 is radioactive and has a half life of 2.23 minutes. What percentage of the sample would be left after 5.28 minutes?
19%
Concentrated sulfuric acid is an aqueous solution having a density of 1.84 g/cm^3 and is 95.0% by mass sulfuric acid. Calculate molarity molality and mole fraction of sulfuric acid,17.8 M,
190 m and 0.78
1. ln K > 0 2. Delta G standard > 0 3. K > 1 4. Delta H standard < T delta S standard Which statement is false, if any?
2
What is bimolecular?
2 reactant molecules
Suppose a sodium 22 nuclide decays into a neon 22 nuclide by emitting a positron. Complete the nuclear chemical equation below so that it describes this nuclear reaction 22/11 Na --->
22/10 Ne + 0/1 e
Fill in the missing symbol in this nuclear chemical equation ? + 1/0 n ---> 24/11 Na + 4/2 He
27/13 Al
Select chemical reaction that has equilibrium constant expression Kc=[NO]^2 [Br2] / [NOBr]^2
2NOBr (g) ------> 2NO (g) + Br2(g)
1. Delta S standard = delta H standard/T 2. Delta G standard=0 3. ln K=-1 4. K=1 Which statement is false if any?
3
Aspirin is a weak acid that ionizes in water according to the equation: HC9H7O4 (aq) + H2O (l) ----> H3O^+ (aq) + C9H7O4^- (aq) A 0.10 M aqueous solution of aspirin has a pH of 2.27 at 25 degrees C. Determine the Ka of aspirin
3.0 * 10^-4
Determine Kb of a weak base if a 0.50 M solution of the base has a pH of 9.59 at 25 degrees C.
3.0 * 10^9
Calculate pH of a 0.065 M solution of a weak acid that has Ka=1.2 * 10^-5
3.05
Calculate solubility for copper (II) iodate if the Ksp value is 1.4 * 10^-7
3.3 * 10^-3
Suppose a 500 mL flask is filled with 1.6 mol of OCl2, 0.50 mol of BrOCl and 1.7 mol of BrCl. The following reaction becomes possible: Br2 (g) + OCl2 (g) ----> BrOCl (g) + BrCl (g) The equilibrium constant K is 7.09. Calculate the equilibrium molarity of OCl2
3.31 M
What is the optimal pH within about 1 pH range that can be buffered by a solution containing acetic acid and sodium acetate?
3.74-5.74
The Ka value for niacin is 1.5 * 10^-5. What is the pH of a 0.010 M niacin solution?
3.87 * 10^-4 M
Fill in the missing symbol in this nuclear chemical reaction ? + 1/1 H ---> 4/2 He + 1/0 e
3/2 He
Mercury and oxygen react to form mercury (II) oxide like this: 2Hg (l) + O2 (g) ---> 2HgO (s) At a certain temperature, a chemist finds that a 7.3 L reaction vessel containing a mixture of mercury, oxygen and mercury (II) oxide at equilibrium has the following composition: Hg=18.6 O2=7.8 g HgO=23.8 g Calcite the value of the equilibrium constant kc for this reaction. Round to 2 sig figs
30
For a certain chemical reaction, the standard Gibbs free energy of reaction is 122 kJ. Calculate the temperature at which the equilibrium constant k=9.5 * 10^-22
30 degrees C
Calculate mass of magnesium proceed upon the application of 60.0 A for 4000 s on a solution of magnesium nitrate
30.2 g
When 56.4 g of urea is dissolved in 1100 g of a certain mystery liquid X the freezing point of the solution is 5.10 degrees C less than the freezing point of pure X. Calculate the mass of sodium chloride that must be dissolved in the same mass of X to produce the same depression in freezing point. The van't Hoff factor I-1.82 for sodium chloride in X
30.2 g
Using standard reaction potentials provided, calculate standard reaction free energy ΔG˚ for the following redox reaction: Mn^2+ (aq) + 2H2O (l) + Br2 (l) ---> MnO2 (s) + 4H+ (aq) +2Br- (aq) Cathode: 1.066 V Anode: 1.224
30.5 kJ/mol
Quinine was the first drug widely used to treat malaria and it remains the treatment of choice for severe cases. A solution prepared by dissolving 10.0 g of quinine in 50.0 mL of ethanol has a freezing pint of 1.55 degrees C below that of pure ethanol. Determine the molar mass of quinine (the density of ethanol is 0.789 g/mL). Assume the quinine is a nonelectrolyte
325 g/mol
Balance the following redox reaction in acidic solution: Zn (s) + NO3- (aq) ----> Zn^2+ (aq) + NO (g)
3Zn (s) + 2NO3- (aq) + *H^+ (aq) ---> 3Zn^2+ (aq) + 2NO (g) + 4H2O (l)
Ammonia will decompose into nitrogen and hydrogen at high temperatures. An industrial chemist styling this reaction fills a 200 mL flask with 1.5 atm of NH3 and when the mix has come to equilibrium measures the partial pressure of hydrogen to be 1.4 atm. Calculate the pressure equilibrium to 2 sig figs.
4.0
Calculate [H3O^+] in a solution in which [OH^-]=0.25 M at 25 degrees C
4.0 * 10^-14 M
A wooden artifact is found to have a carbon 14 activity of 9.1 disintegrations per second. Given that carbon 14 activity of an equal mass of fresh cut wood has a constant value of 15.2 disintegrations per second, determine the age of the artifact. The half life of carbon 14 is 5715 years
4.2 * 10^3 years old
Determine the pH at 25 degrees C of a solution that is prepared by dissolving 0.075 mol of sodium acetate in 1.0 L of a 0.25 M acetic acid. Assume that the addition of sodium acetate doesn't change the volume of the solution
4.22
Suppose a 250 mL flask is filled with 0.10 mol of I2 and 1.7 mol HI. The following reaction becomes possible H2 (g) + I2 (g) ---> 2HI (g) The equilibrium constant K for this reaction is 8.62 at the temperature of the flask. Calculate the equilibrium molarity of HI
4.27 M
A buffer solution contains 0.50 M acetic acid Ka=1.8 * 10^-5 and 0.20 M sodium acetate. Calculate pH of this solution
4.34
Determine the pH at 25 degrees C of a solution prepared by adding 0.050 mole of sodium acetate to 1.0 L of 0.10 M acetic acid. Assume that the addition of sodium acetate doesn't change the volume of the solution
4.44
Calculate solubility of PbCrO4 in water at 25 degrees . Ksp=2.00 * 10^-14. Round to 2 sig figs
4.6 * 10^-5 g/L
Calculate the rate constant for the first order decay of ^24 Na (t1/2=14.7 h)
4.7*10^-2/h
The Ka of HClO is 3.5 * 10^-8. Calculate the pH of a solution at 25 degrees C that is 0.0075 M in HClO
4.79
Calculate the solubility of Ni(OH)2 in water at 25 degrees C. Ksp=5.48 * 10^-16. Round to 2 sig figs
4.8 * 10^-4 g/L
Starting with 1.00 L of a buffer that is 1.00 M in acetic acid and 1.00 M in sodium acetate, calculate pH after the addition of 0.100 mole of NaOH. Assume the addition doesn't change the volume of the solution
4.83
Calculate the pH at 25 degrees C of a 0.83 M solution of (CH3)3NHCl. Note that it is a weak base with pKb of 4.19
4.9
The solubility of CuBr in water at 25 degrees C is measured to be 0.010 g/L. Use this information to calculate Ksp. Round to 2 sig figs
4.9 * 10^-9
An aqueous solution at 25 degrees C has a pH of 9.05. Calculate pH
4.95
Fill in the missing symbol in this nuclear chemical equation 239/94 Pu + ? ---> 242/96 Cm + 1/0 n
4/2 He
Fill in the missing symbol in this nuclear chemical equation 180/14 W ---> 176/72 Hf + ?
4/2 He
What is the symbol for an alpha particle?
4/2 He or 4/2 a
Calculate the vapor pressure of water over a solution made by dissolving 225 g of glucose in 575 g of water at 35 degrees C (P degrees H2O = 42.2 mmHg)
40.6 mmHg
Rate constants for the reaction CO (g) + NO2(g) ----> CO2 (g) + NO (g) were measured at 4 different temperatures. The data is shown in the table. Determine activation energy (in kJ/mol) for this reaction k. T 0.0521. 228 0.101. 298 0.184. 308 0.332. 316
46 kJ/mol
An electric current of 0.940 A transports 450 µC of charge. Calculate the time this took
479 µs
Permanganate ion and iodide ion react in basic solution to produce manganese (IV) oxide and molecular iodine. Use the half reaction method to balance the equation: MnO4- + I- ----> MnO2 + I2
4H2O + 2MnO4- + 6I- ---> 2MnO2 + 3I2 + 8OH-
Write a balanced half reaction for the reduction of permanganate ion, (MnO4-) to solid manganese dioxide (MnO2) in acidic aqueous solution. Be sure to add physical state symbols where appropriate
4H^+ (aq) + 3e- + MnO4- (aq) ---> MnO2 (s) + 2H2O (l)
Write a half reaction of the oxidation of liquid water to gaseous oxygen (O2) in basic solution. Be sure to add physical state symbols where appropriate
4OH- (aq) ---> O2 (g) + 2H2O (l) + 4e-
Calculate pH of 1 L of a buffer that is 1.0 M in acetic acid and 1.0 M in sodium acetate after addition of 0.25 mole of NaOH
5.0
Calculate pH of a 0.10 M solution of ammonium chloride at 25 degrees C
5.12
Calculate the pH at the equivalence point when 25.0 mL of 0.100 M of NH3 is titrated with 0.100 M HCl
5.28
An aqueous solution at 25 degrees C has a pOH of 8.7. Calculate pH
5.3
Caffeine, the stimulant in coffee and tea, is a weak base that ionizes in water according to the equation: C8H10N4O2 (aq) + H2O (l) ----> HC8H10N4O2^+ (aq) + OH^- (aq) A 0.15 M solution of caffeine at 25 degrees C has a pH of 8.45. Determine the Kb of caffeine
5.3 * 10^-11
Calculate Kp for the reaction 2NO (g) + O2 (g) ---> 2NO2 (g) at 25 degrees C using thermodynamic values
5.3 * 10^12
Calculate the boiling point and freezing point of a solution of antifreeze that is 40.0% by mass ethylene glycol C2H6O2
5.50 degrees C and 105.5 degrees C
Calculate Ka of a weak acid if a 0.015 M solution of the acid has a pH of 5.03 at 25 degrees C
5.8 * 10^9
Determine the change in entropy for 1.0 mol of an ideal gas originally confined to 1/2 of a 5.0 L container when the gas is allowed to expand the entire container at constant temperature
5.8 J/K
A certain substance X has a normal freezing point of -6.2 degrees C and a molal freezing point depression constant Kf=7.04 degrees C*kg/mol. A solution is prepared by dissolving some urea in 950 g of X. The solution freezes at -12.7 degrees C. Calculate mass of urea dissolved
53 g
The equilibrium constant Ksp for the dissociation of AgCl in H2O at 25 degrees C AgCl (s) ----> Ag^+ (aq) + Cl^- (aq) is 1.6 * 10^-10. Calculate standard delta G for this process
55.9 kJ/mol
Write the balanced nuclear equation for the reaction represented by 56/26 Fe (d,a) 54,25 Mn, where d represents a deuterium nucleus
56/26 Fe + 2/1 H ---> 54/25 Mn + 4/2 a
Use the half reaction method to balance the following equation in acidic solution: Fe^2+ + MnO4- ---> Fe^3+ + Mn^2+
5Fe^2+ + MnO4- + 8H+ ----> 5Fe^3+ + Mn^2+ + 4H2O
Calculate the equilibrium constant for the following reaction at 25 degrees C: Sn (s) + 2Cu^2+ (aq) ----> Sn^2+ (aq) + 2Cu^+ (aq) The standard reduction potential values are: Cathode: 0.15 V Anode: -0.14 V
6 * 10^9
2H2O (g) + 2H2 9g) + O2 (g) Delta H = 484 kJ Delta S = 1696 J/K Calculate Delta G and determine spontaneity
6 kJ and the reverse reaction is spontaneous
4.9 g + 1.170 g
6.1 g
Use Q to predict if reaction is at equilibrium. If the reaction is not at equilibrium, in which direction must it proceed in order to achieve equilibrium? CO (g) + 3H2 (g) ----> CH4 (g) + H2O (g) Concentrations are: 0.020 M CO, 0.020 M H2, 0.0010 M CH4, and 0.0010 M H2O; Kc=3.92
6.25
The pH of a 1.0 M solution of benzoic acid is measured to be 2.10. Calculate Ka of benzoic acid. Round to 2 sig figs
6.3 * 10^-5
For a certain chemical reaction, the standard Gibbs free energy of reaction at 25.0 degrees C is -113 kJ. Calculate equilibrium constant K for this reaction. Round to 2 sig figs
6.3 * 10^19
A certain substance X has the normal boiling point of 144.3 degrees C and a molal boiling point elevation constant Kb=1.75 degrees C*kg/mol. Calculate boiling point of a solution made of 67.38 g of urea dissolved in 700 g of X
6.3 degrees C * kg/mol
399.4 mol / 0.61 s
6.5 * 10^2 m/s
A solution is prepared by dissolving 50.0 g of hemoglobin (Hb) in enough water to make 1.00 L of solution. The osmotic pressure of the solution is measured and found to be 14.3 mmHg at 25 degrees C. Calculate the molar mass of hemoglobin
6.50 * 10^4 g/mol
If the hydronium concentration is 2.7 * 10^-7 M. What is pH?
6.57
Calculate Ksp of MgF2 if the solubility of this compound is 1.2 * 10^-3 M
6.9 * 10^-9
Ringer's lactate a solution containing several different salts is often administered intravenously for the initial treatment of trauma patients. One liter contains 0.102 mol of sodium chloride, 4 * 10^-3 mol of potassium chloride, 1.5 * 10^-3 mol of calcium chloride and 2.8 * 10^-2 mole of sodium lactate. Determine the osmotic pressure of this solution at normal body temperature (37 degrees C). Assume no ion pairing. The formula for the lactate ion is CH3CH2COO^-
6.93 atm
Balance this redox reaction in basic solution: Fe3O4 + MnO4- ---> Fe2O3 + MnO2
6Fe3O4 +H2O + 2MnO4- ---> 9Fe2O3 + 2MnO2 + 2OH-
Using the data from appendix 2, calculate equilibrium constant Kp for the following reaction at 25 degrees C 2H2O (l) ----> 2H2 (g) + O2 (g)
7 * 10^-84
Cobalt 60 is radioactive and has a half life of 5.26 years. How long would it take a sample to decay from 5.20 mg to 2.00 mg
7.2 years
If the hydronium concentration is 5.7 * 10^-8, what is the pH?
7.24
A layer of silver is electroplated on a piece of cutlery using a constant current of 0.100 A. How much time is required to deposit 3.00 g silver?
7.45 hr
0.15 g of protein is dissolved in water to yield 2.0 mL of solution. pi is 18.6 torr at 25.0 degrees C. Calculate molar mass of protein
7.5 * 10^4 g/mol
Calculate the rate constant at 200 degrees C for a reaction that has a rate constant of 8.1 * 10^-4 * s^-1 at 90 degrees C and an activation energy of 59 kJ/mol
7.6*10^-2/s
The rate constant of a certain reaction is known to obey the Arrhenius equation and to have an activation energy of Ea = 26.0 kJ/mol. If the rate constant of this reaction is 6.1*10^7 M^-1 * s^-1 at 340.0 degrees C. What will the rate constant be at 370.0 degrees C. Round to 2 sig figs
7.7 * 10^7 M^-1 * s^-1
The solubility of Fe(OH) 2 in water at 25 degrees C is measured to be 5.2 * 10^-4 g/L. use this information to calculate Ksp
7.8 * 10^-16
What is the concentration of KOH for which the pH is 11.89?
7.8 * 10^-3
The rate constant for the reaction: 2A--->B is 7.5*10^-3 s^-1 at 110 degrees C. The reaction if first order with respect to A. How long (in seconds) will it take for [A] to decrease from 1.25 M to 0.71 M
75 s
A solution that is 0.100 M in hydrofluoric acid has an osmotic pressure of 2.64 atm at 25 degrees C. Calculate the percent ionization of HF at this concentration
8%
Calculate the pH of a 0.10 M solution of NaF at 25 degrees C
8.05
An electric current of 37.10 A flows for 22.0 seconds. Calculate amount of electrical charge transported
8.16 * 10^2 C
Calculate the pH of 0.20 M NaF
8.22
Calculate [OH^-] in a solution in which [H3O^+]=0.0012 M at 25 degrees C
8.3 * 10^-2 M
Calculate the pH at 25 degrees C is a 0.16 M solution of a weak base with Kb=2.9 * 10^-11
8.33
If the hydronium concentration is 2.3 * 10^-9, what is the pH?
8.64
For the following reaction rate rate=k[A]^2 and k=1.3*10^-2 M^-1*s^-1 A+B--->2C Use this information to fill in the missing table entries Experiment. [A] (M). [B](M). Initial Rate (M/s) 1. 0.013. 0.250 2.20* 10^-6 2. 0.026. 0.250. ? 3. ?. 0.500. 2.20*10^-6
8.8*10^-, 0.013 M
Determine pH of a 0.15 M solution of sodium acetate at 25 degrees C
8.96
Suppose a yttrium 88 nuclide transforms into a strontium 88 nuclide by absorbing an electron and emitting a gamma ray. Complete the nuclear chemical equation below so that it describes this nuclear reaction ---> 88/38 Sr + 0/0 gamma
88/39 Y + 0/-1 e
The normal boiling point of Br2 (l) is 58.8 degrees C and its enthalpy of vaporization if 29.6 kJ/mol. Calculate delta S when 1.0 mol bromine is vaporized at 58.8 degrees C
89.2 J/K
The half life for the decay of carbon 14 is 5.73 * 10^3 years. Suppose the activity due to the radioactive decay of the carbon 14 in a tiny sample of an artifact made of wood from an archeological dig is measured to be 2.4 * 10^3 Bq. The activity in a similar sized sample of fresh wood is measured to be 7.1 * 10^3 Bq. Calculate the age of the artifact to 2 sig figs
9.0 * 10^3 years
Given the rate law rate=k[A] and k=0.018 s^-1 determine the rate when [A]=0.50 M and [B]=0.25 M
9.0*10^-2 M/s
0.091 g/L = ? mg/dL
9.1
9.1 * 10^6 mol/kg*m^2 = ? mol/g*cm^2
9.1 * 10^-1
Determine the pH at 25 degrees C of a solution prepared by dissolving 0.35 mole of ammonium chloride in 1.0 L of 0.25 M ammonia
9.11
Calculate pH at 25 degrees C if a 0.0028 M solution of a weak base with a Kb of 6.8 * 10^-8
9.14
Calculate pH at 25 degrees C solution of KC4H7CO2. Note that it is a weak acid with a pKa of 4.82. Round to 1 decimal place
9.3
The solubility of BaSO4 in water at 25 degrees C is measured to be 0.0023 g/L. Use this Information to calculate Ksp for BaSO4. Round to 2 sig figs
9.7* 10^-11
The rate constant for a particular first order reaction is given for three different temperatures T. k 400. 2.9*10^-3 450. 6.1*10^-2 500. 7.0*10^-1 Using the data calculate activation energy
91 kJ/mol
In the industrial "chlor-alkali" process, pure chlorine and sodium hydroxide are proceed by electrolyzing brine, essentially an aqueous solution of sodium chloride. Suppose a current of 430 A is passed through an aqueous solution of NaCl for 62.0 seconds. Calculate mass (in mg) of pure chlorine produced. Be sure the answer has a unit symbol and is the correct number of sig figs
979 mg
The reaction 2N2O5 (g) ----> 4NO2 (g) + O2(g) Was studied at several temperatures and the following values of k were obtained. Calculate the value of Ea for this reaction k. T 2.0*10^-5. 293 7.2*10^-5. 303 2.7*10^-4. 313 9.1*10^-4. 323 2.9*10^-3. 333
99.8 kJ/mol
The technetium 99 nuclide radioactively decays by beta emission. Write a balanced nuclear chemical equation that describes this process
99/43 Tc ---> 99/44 Ru + 0/-1 e
A substance that is an electron acceptor is classified as
A Lewis acid
Which of the following compounds will be more soluble in acidic solution than in water (a) CuS (b) AgCl (c) PbSO4
A and C are more soluble in acid than water. AgCl is no more or less soluble in acid than water
What is a heterogenous catalyst?
A catalyst that is in a different phase from the reactants
What is an electrolytic cell?
A cell that uses an external voltage source to create an electric current that forces a nonspontaneous reaction to occur. This is known as electrolysis. The anode is positive and the cathode is negative, whereas in a galvanic cell the anode is negative and the cathode is positive
What is a colloid?
A dispersion of particles of one substance throughout another substance
What is a curie Ci?
A measure of the activity of the radioactive material, one curie is equivalent of 3.7x10-10 disintegrations per second.
What is an ion pair?
A negatively charged and a positively charged ion that combine to become stable
What is a second order reaction?
A second-order reaction is a reaction whose rate depends on concentration of one reactant raised to the second power or the on the product of the concentrations of two different reactants (each raised to the first power)
What is a supersaturated solution?
A solution that contains more solute than it can theoretically hold at a given temperature
What is a salt bridge?
A source of unreactive counterions to balance out charge between anode and cathode solution
What does solubility refer to?
A specific solute, a specific solvent and a specific temperature
What is a catalyst?
A substance which increases the speed of a reaction, without being changed or used up in the reaction
What are emulsions?
A suspension of insoluble droplets of one liquid in another liquid.
What does an aqueous solution of a weak electrolyte contain?
A weak electrolyte and it's ionization products
For each solute click the button under the better solvent A) Solute= (NH2)2 Solvent=(CH3CH2)3N or (CH3)2CO B) Solute=NaCl Solvent= CH3(CH2)4CH3 or H2O C) Solute=C6H12O6 Solvent=C4H8O or CH3OH
A) (CH3)2CO B) H2O C) CH3OH
For each process, determine the sign of Delta S for the system (a) decomposition of CaCO3 (s) to give CaO (s) and CO2 (g) (b) heating bromine vapor from 45 degrees C to 80 degrees C (c) Condensation of water vapor on a cold surface (d) reaction of NH3 (g) and HCl (g) to give NH4Cl (s) and (e) dissolution
A) + B) + C) - D) - E) +
Determine the pH of a solution at 25 degrees C in which the hydroxide concentration is (a) 8.3 * 10^-15 M (b) 3.3*10^-4 M and (c) 1.2 * 10^-3 M.
A) -0.08 B) 10.52 C) 11.08
The decomposition of hydrogen peroxide is first order in H2O2 2H2O2 (aq) ----> 2H2O (l) + O2(g) The rate constant for this reaction at 20 degrees C is 1.8*10^-5 s^-1. If the starting concentration of H2O2 is 0.75 M determine (a) the concentration of H2O2 remaining after 3 hours and (b) how long it will take for the H2O2 concentration to drop to 0.10 M
A) -0.1944 B) 31 hours
Consider the hypothetical chemical reaction: A + B = C+D A+B are at 300 C+D are at 200 A) What is the heat of reaction? B) Is this reaction endothermic or exothermic? C) Can you determine activation energy? D) Can you determine the energy of the reverse reaction?
A) -100 kJ/mol B) Exothermic C) 100 kJ/mol D) Yes its 200 kJ/mol
The standard reaction energy delta G standard = 70 kJ for this reaction: MgCl2 (s) + H2O (l) ----> MgO (s) + 2HCl (g) Use this information to complete the table below. Round each to nearest kJ A) 2MgO (s) + 4HCl (g) ----> 2MgCl2 (s) + 2H2O (l) b) MgO (s) + 2HCl (g) -----> MgCl2 (s) + H2O (l) C) 1/4 MgCl2 (s) + 1/4 H2O (l) ---> 1/4 MgO (s) + 1/2 HCl (g)
A) -140 kJ B) -70 kJ C) 18 kJ
Consider the reaction: 4NO2 (g) + O2 (g) ---> 2N2O5 (g) At what particular time during the reaction nitrogen dioxide is being consumed at the rate of 0.00130 M/s. (a) At what rate is molecular oxygen being consumed (b) At what rate is dinitrogen peroxide being produced?
A) -3.25* 10^-4 M/s B) 6.50*10^-4 M/s
Consider the reaction between nitrogen and oxygen gas to form dinitrogen monoxide 2N2 (g) + O2 (g) ----> 2N2O (g) Delta H reaction = +163.2 kJ A) Calculate the entropy change in the surroundings associated with this reaction occurring at 25 degrees C B) Determine the sign of the entropy change for the system C) Determine the sign of the entropy change for the universe. Will the reaction be spontaneous?
A) -548 J/K B) Negative C) Negative, so no
Calculate standard free-energy changes for the following reactions at 25 degrees C A) CH4 (g) + 2O2 (g) ----> CO2 (g) + 2H2O (l) B) 2MgO (s) ----> 2Mg (s) + O2 (g) CH4 (g) = -50.8 kJ/mol CO2 (g) = -394.4 kJ/mol H2O (l) = -237.2 kJ/mol MgO (s) = -569.6
A) -818.0 kJ/mol B) 1139 kJ/mol
Use the following information to answer the questions A+B---->C+D and the experimental rate law is rate=k[B]^2 A) What is the order of reaction with respect to A and B B) What is the overall order of the reaction?
A) 0 and 2 B) 2
Determine the initial concentration for the reaction 2A---> B with a rate constant of 32.0 M^-1*s^-1 necessary for half life to be (a) 1.50 s (b) 25.0 s (c) 175 s
A) 0.00200 M B) 1.25*10^-3 M C) 1.79*10^-4 M
The decomposition of H2O2 in dilute base is first order with k=1.8 * 10^-5 s^-1 at 20 degrees C A) If the initial concentration of hydrogen peroxide is 0.30 M what is the concentration after 4.0 hours? B) How long will it take for the concentration to drop to 0.12 M? C) Calculate half life of the hydrogen peroxide decomposition at 20 degrees C D) how many hours will it take for the concentration to drop to 25.0% of its initial value?
A) 0.23 M B) 14 hours C) 11 hours D) 21 hours
Calculate pOH of the following aqueous solutions at 25 degrees C (a) 0.15 M NaOH (b) 8.4 * 10^-3 M RbOH (c) 1.7 * 10^-5 CsOH
A) 0.82 B) 2.08 C) 4.77
From the standard entropy values CaCO3 (s) = 92.9 J/K*mol, CaO (s) = 39.8 J/K*mol, CO2 (g) = 213.6 J/K * mol, N2 (g) = 191.5 J/K*mol, H2 (g) =131.0 J/K* mol, NH3 (g) = 193.0 J/K*mol, Cl2 (g) = 223.0 J/K*mol, HCl (g)= 187.0 J/K * mol, calculate standard entropy changes for the following reactions at 25 degrees C A) CaCO3 (s) -----> CaO (s) + CO2 (g) B) N2 (g) + 3H2 (g) ----> 2NH3 (g) C) H2 (g) + Cl2 (g) + 2HCl (g)
A) 160.5 J/K * mol B) -198.5 J/K * mol C) 20.0 J/K * mol
The rate law of a certain reaction is given by the following rate law: rate=k[H2]^2[NH3] Use this information to answer the following questions A) What is the reaction order for H2? B) what is the reaction order in NH3? C) What is the overall reaction order? D) At a certain concentration of H2 and NH3 the initial rate of reaction is 32.0 M/s. What would the initial rate be if the concentration of H2 were doubled? E) The rate of reaction is measured to be 0.800 M/s when [H2]=0.43 and [NH3]=0.16 M. Calculate value of rate constant
A) 2 B) 1 C) 3 D) 128 M/s E) 2.7*10^1 M^-2 * s^-1
Ancient statues are made of marble (a form of calcium carbonate) are damaged by acid rain because of the reaction between sulfuric acid in the rain and calcium carbonate produces soluble calcium sulfate which washes away CaCO3 (s) + H2SO4 (aq) -----> CaSO4 (aq) + CO2 (g) + H2O (l) Suppose an engineer decides to study the rate of this reaction. He prepares four vessels by adding 179.7n g of solid calcium carbonate and 62 mL of 5.0 M sulfuric acid solution to each and then filling the remainder of the vessel with distilled water. The volume and temperature of each vessel is show in the table below. Arrange the reaction vessel by decreasing order of initial rate of reaction. In other words, select a 1 next to the vessel in which the engineer can reasonably expect the initial rate of reaction to be highest, a 2 next to the vessel in which the initial rate of reaction would be the next highest and so on. A: 2.0 L volume 26.0 degrees C B: 2.0 L volume 28.0 degrees C C: 4.0 L volume 26.0 degrees C D: 4.0 L volume 25.0 degrees C
A) 2 B) 1 C) 3 D) 4
Use the information provided to sort the following species by oxidizing power A) Ag (aq) 0.80 V B) Zn^2+ (aq) -0.762 V C) Mg^2+ (aq) -0.237 V D) Br2 (L) 1.08 V
A) 2 B) 3 C) 4 D) 1
Consider the following data on some weak acids and weak bases: Nitrous acid, HNO2, Ka=4.5 * 10^-4 Acetic acid, HCH3CO2, Ka=1.8 * 10^-5 aniline, C6H5NH2, Kb=4.3 * 10^-10 pyridine, C5H5N, Kb= 1.7 * 10^-9 Use this data to rank the following solutions in order of increasing pH. 1 is the lowest, 4 is the highest A) 0.1 M C5H5NHBr B) 0.1 M KCH3CO2 C) 0.1 M NaI D) 0.1 M C6H5NH3Cl
A) 2 B) 4 C) 3 D) 1
At what concentration does hydrocyanic acid exhibit (a) 0.05% ionization (b) 0.10% ionization and (c) 0.15% ionization?
A) 2.0 * 10^-3 M B) 4.9 * 10^-4 M C) 2.2 * 10^-4 M
Given that something has 92 protons and 146 neutrons A) What is the nuclide? B) What is the value of Z? C) What is the value of A?
A) 238/92 U B)92 C) 238
Consider the electrochemical cell having the notation below Fe (s) | Fe^2+ (aq) || O2 (g) | H+ (aq), H2O (l) | Pt (s) Cathode: 0.45 Anode=-1.23 A) Write overall cell reaction B) Calculate standard reduction potential of cell
A) 2Fe (s) + O2 (g) + 4H+ (aq) ---> 2Fe^2+ (aq) + 2H2O (l) B) 1.68 V
Consider the following mechanism for the reaction of nitric oxide: (1) H2 (g) + 2NO (g) ---> N2O (g) + H2O(g) (2) H2 (g) + N2O (g) ----> N2 (g) + H2O (g) A) Write Overall Equation for reaction B) Are there any intermediates C) If there are write down their formulas,
A) 2H2 (g) + 2NO (g) ----> 2H2O (g) + N2 (g) B) Yes C) N2O
The gas phase decomposition of nitrous oxide (N2O) is believed to occur in 2 steps: N2O -----> N2 + O N2O -----> N2 + O2 Experimentally the rate law is found to be rate=k[N2O]. (a) Write the equation for the overall reaction (b) identify the intermediates (c) identify the rate determining step
A) 2N2O ---> 2N2 + O2 B) O C) Step one is the rate determining step because its rate law is the same as the experimental rate law
Suppose the formation of nitrosyl chloride proceeds by the following mechanism (1) NO (g) + Cl2 (g) ----> NOCl2 (g) k1 (2) NOCl2 (g) + NO (g) ----> 2NOCl (g) k2 The first step is much slower than the second A) write the balanced equation for the overall reaction B) Write the experimentally observable rate law for the overall reaction
A) 2NO (g) + Cl2 (g) ---> 2NOCl (g) B) rate=k[NO][Cl2]
Consider the following data on some weak acids and bases Nitrous acid, HNO2, Ka=4.5 * 10^-4 Hydrocyanic acid, HCN, Ka= 4.9 * 10^-10 pyridine, C5H5N, Kb= 1.7 * 10^-9 aniline, C6H5NH2, Kb=4.3 * 10^-10 Use this data to rank the following solutions in order of increasing pH. 1 is the lowest, 4 is the highest A) 0.1 M NaNO3 B) 0.1 M NaNO3 C) 0.1 M KCN D) 0.1 M C6H5NH3Cl
A) 3 B) 2 C) 4 D) 1
Use the information provided to sort the following chemical species by reducing power A) Al (s) -1.676 V B) Zn (s) -0.762 V C) Na (s) -2.71 V D) Ca (s) -2.868 V
A) 3 B) 4 C) 2 D) 1
Determine the pH of a solution at 25 degrees C in which the hydronium ion concentration is (a) 3.5 * 10^-4 M (b) 1.7 * 10^-7 M and (c) 8.8 * 10^-11 M
A) 3.46 B) 6.77 C) 10.06
The equilibrium concentration at 127 degrees C are [NH3]=3.1*10^-2 M, [N2]=8.5 * 10^-1 M, and [H2]= 3.1 * 10^-3 M. For this reaction: N2 (g) + 3H2 (g) ----> 2NH3 (g) A) Calculate Kc B) Calculate Kc' for 2NH3----> N2 (g) + 3H2 (g) C) Calculate Kc" for 1/2 N2 (g) + 3/2H2 (g) -----> NH3 (g) D) Calculate Kp for the original reaction at 127 degrees C
A) 3.8*10^4 B) 2.6 * 10^-5 C) 1.9*10^2 D) 35
Given 72/32 Ge A) What is the amount of protons? B) What is the amount of neutrons? C) What is the value of Z? D) What is the value of A?
A) 32 B) 41 C) 32 D) 73
Predict what redox reaction will take place, if any, when molecular bromine Br2 is added to (a) a 1 M solution of NaI and (b) a 1 M solution of NaCl (assume a temp of 25 degrees C)
A) Because the reaction potential of Br2 is greater than that os I2, Br2 will be reduced to Br^- and I^- will be oxidized to I2. Thus the preceding reaction will occur B) The reduction potential of Br2 is smaller than that of Cl2 so this reaction will not occur. Cl2 is more readily reduced than Br2, so Br2 will not be reduced by Cl^-
Determine for each solute whether the solubility will be greater in waterwhich is polar, or in benzene, which is nonpolar. A) Bromine (Br2) B) Sodium iodide (NaI) C) Carbon tetrachloride (CCl4) D) Formaldehyde (CH2O)
A) Benzene B) Water C) Benzene D) Water
Label each as an acid, base, conjugate base or conjugate acid a) HF (aq) + NH3 (aq) ----> F^- (aq) + NH4^+ (aq) B) CH3COO^- (aq) + H2O (l) ----> CH3COOH (aq) + OH^- (aq)
A) HF is the acid, NH3 is the base. F^- his the conjugate base and NH4^+ is the conjugate acid B) CH3COO^- is the base and H2O is the acid. CH3COOH (aq) is the conjugate acid OH^- is the conjugate base
HClO3 A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) Hypochlorous Acid B) Weak Acid C) HClO (aq) + H2O (l) ClO- (aq) + H3O + (aq) D) Ka=3.5 * 10^8 E) pH=4.10
Predict what will be observed in each experiment below A) Rock candy is formed when excess sugar is dissolved in hot water followed by crystallization. A student wants to make 2 batches of rock candy. he finds an unopened box of cane sugar in the pantry. He starts preparing batch A by dissolving sugar in 500 mL of hot water (70 degrees C). He keeps adding sugar until no more sugar dissolves in the hot water. He cools the solution to room temperature. He prepares batch B by dissolving sugar in 500 mL of water at room temperature until no more sugar is dissolved. He lets the solution sit at room temperature 1. It is likely more of the candy will be formed in batch A 2. It is likely less candy will be formed in batch A 3. It is likely no rock candy will form at all 4. I need more information B) A student sees tiny bubbles clinging to the inside of an unopened bottle full of carbonated soft drink. The student squeezes the bottle 1. bubbles will shrink and some may vanish 2. bubbles will grow and more may appear 3. The bubbles won't change 4. I need more information
A) It is likely more of the candy will be formed in batch A B) Bubbles will shrink and some may vanish
Predict whether a precipitate will from when each of the following is added to 650 mL of 0.0080 M K2SO4 (a) 250 mL of 0.0040 BaCl2 (b) 175 mL of 0.15 M AgNO3 (c) 325 mL of 0.25 M Sr(NO3)2. Assume volumes were additive
A) It will precipitate b) It won't precipitate C) It will precipitate
Carbonyl Chloride (COCl2) also called phosgene, is a highly poisonous gas that was used on the battle field of World War I. It is produced by the reduction of carbon monoxide with chlorine gas: CO(g) + Cl2 (g) ------><------- COCl2 (g) In an experiment conducted at 74 degrees C, the equilibrium concentrations of the species involved in the reaction were as follows [CO]=1.2*10^-2 M, [Cl]=0.054 M, and [COCl2]=0.14 M (a) Write the equilibrium expression and (b) determine the value of the equilibrium constant for this reaction at 74 degrees C
A) Kc= [COCl2] / [CO][Cl2] B) 2.2 * 10^2
Write equilibrium expressions for each of the following: A) CaCO3 (s) -----><---- CaO (s) + CO2 (g) B) Hg (l) + Hg^2+ (aq) ----><----- Hg2^2+ (aq) C) 2Fe (s) + 3H2O (l) ------><------Fe2O3 (s) + 2H2 (g) D) O2 (g) + 2H2 (g) ------><------ 2 H2O (l)
A) Kc=[CO2] B) Kc=[Hg2^2+]/[Hg^2+] C) Kc = [H2]^2 D) Kc = 1/ [O2] [H2]^2
Write the Kp expressions for A) PCl3 (g) + Cl2 (g) ------><-----PCl5 (g) B) O2 (g) + 2H2 (g) ------><------2H2O (l) C) F2 (g) + H2 (g) -----><-------2HF (g)
A) Kp = (PPCl5) / (PPCl3)(PCl2) B) Kp = 1/ (PO2) (PH2)^2 C) Kp (PHF)^2 / (PF2) (PH2)
For each product in what direction will the equilibrium shift when the volume of the reaction vessel is decreased A) PCl5 (g) ------><------ PCl3 (g) + Cl2 (g) B) 2PbS(s) + 3O2 (g) ------><----2PbO (s) + 2SO2 (g) C) H2 (g) + I2 (g) + 2HI (g)
A) Left B) right C) no change
The gas-phase reaction of nitric oxide with hydrogen at 1280 degrees C is 2NO (g) + 2H2 (g) ----> N2 (g) + 2H2O (g) From the following data collected at 1280 degrees C determine (a) the rate law (b) the rate constant including units and (c) the rate of the reaction when [NO]=4.8 * 10^-3 M Experiment. [NO] M. [H2] M. Initial Rate M/s 1. 5.0* 10^-3. 2.0*10^-3. 1.3*10^-5 2. 1.0*10^-2. 2.0*10^-3. 5.0*10^-5 3. 1.0*10^-2. 4.0*10^-3. 1.0*10^-4
A) rate=k[NO]^2[H2] B) 2.6*10^2 M^-2 * s^-1 C) 3.7*10^-5 M/s
The reaction of peroxydisulfate ion (S2O8^-2) with iodine ion (I^-) is S2O8^-2 (aq) + 3I^- (aq) ----> 2SO4^2- (aq) + I3^- (aq) From the following data collected at a certain temperature determine the rate law and calculate the rate constant, including its unit Experiment. [S2O8 ^2-] (M). [I](M). Initial Rate (M/s) 1. 0.080. 0.034 2.2*10^-4 2. 0.080. 0.017. 1.7*10^-4 3. 0.16. 0.017. 2.2*10^-4
A) rate=k[S2O8^2-][I^-] B) 8.1*10^-2 M^-1*s^-1
For the dissociation of an ionic solid in water, the following conditions may exist:
A) solutions may be unsaturated B) solutions may be saturated C) solutions may be supersaturated
Consider the reaction 4PH3 (g) ----> P4(g) + 6H2 (g) A) Determine rate of reaction B) At a particular point during the reaction molecular hydrogen is being formed at a rate of 0.168 M/s. At what rate is P4 being produced? C) At what rate is PH3 being consumed
A) t delta [H2]/6 delta t B) 2.80 * 10^-2 M/s C) 1.12 * 10^-1 M/s
A chemist is studying the following equilibrium, which has the given equilibrium constant at a certain temperature 2NO (g) + Cl2 (g) ----> 2NOCl (g) Kp=4 * 10^-6 He fills a reaction vessel at this temperature with 15 atm of NO gas and 13 atm of Cl2. Use this data to answer the questions in the table below A) Can you predict the equilibrium pressure of NOCl, using only the tools available B) If you said yes, then enter the equilibrium pressure of NOCl at right. Round to 1 sig fig
A) yes B) 0.1 atm
For a certain reaction Delta H = 178 kJ and delta S = 160 J/K. What is the minimum temperature at which this process becomes spontaneous
Above 1113 K
HCH3CO2. What's the name? Ionic or molecular? Strong or weak acid/base?
Acetic acid, molecular and a weak acid
Determine if NH4Br is acidic, basic or neutral
Acidic
Is CH3NH3Cl basic, acidic or neutral?
Acidic
Is Fe(NO3)3 basic, acidic or neutral?
Acidic
determine if Fe(ClO4)3 is acidic, basic or neutral
Acidic
Electronegativity of X
Acidic strength increases with the electronegativity of the central atom
What is the different between a catalyzed and an uncatalyzed reaction?
Activation is higher in reaction without a catalyst
What is defined as stress?
Addition of reactant/product, removing of reactant/product, change in volume and change in temperature
What is the Haber process?
Ammonia production Nitrogen + Hydrogen Ammonia N2 (g) + 3H2 (g) -->2NH3 (g)
In electrolyte solutions how must the colligative property equation be modified?
An (i) must be added to the equation
What is a fuel cell?
An electrical cell that's been supplied with a fuel and oxygen (or air) and uses energy from the reaction between them to produce electrical energy efficiently When the fuel enters the cell, it becomes oxidised and sets up a partial charge within the cell
What is a galvanic cell?
An electrochemical cell that produces electricity as a result of a *spontaneous reaction*
What is an unsaturated solution?
Any solution that can dissolve more solute at a given temperature
Equilibrium constants
Are unitless
What does Raoult's law state?
As solute is added to a solvent, the vapor pressure of the solvent decreases proportionately
What does bottom number mean?
Atomic number (number of protons)
Which solution has the highest boiling point? A) 0.15 m CH3OH B) 0.20 m KBr C) 0.10 m Na2SO4 D) pure water
B
Which stamen about acid and bases is not true? A) Lewis acid and base reactions do not require water B) a strong acid has a strong conjugate base C) A substance that is amphoteric can act as both a Bronsted acid and base D) Weak bases often contain nitrogen E) Strong bases ionize completely in water
B
Which statement about equilibrium is not true A) forward and reverse reactions are equal B) the concentrations of the reactants and products are equal C) can be achieved with reactants, products or a mix of the two D) forward and reverse reactions proceed E) concentrations of reactants and products don't change
B
Which statement is not true about a solution with pH=12.00. A) [OH^-]=1.0 * 10^-2 M B) [H3O ^ +]> [OH^-] C) H3O ^ + = 1.0 * 10^-12 D) pOH=2.00 E) this solution is basic
B
Barium hydroxide. What's the formula? Is it ionic or molecular? Strong or weak acid/base?
Ba(OH)2, ionic and strong base
Ba(OH)2. What's the name? Is it ionic or molecular? Strong or weak acid/base?
Barium hydroxide, ionic and strong base
Determine if NaClO is acidic, basic or neutral
Basic
What statements are true about rate determining steps of reactions? A) Fastest step b) Always termolecular C) slowest step D) can be either fast or slow E) Must give same rate law as overall reaction
C and E
Identify the Lew acid and base among the reactants: C2H5OC2H5 + AlCl3 --> (C2H5)2OAlCl3
C2H5OC2H5=Base AlCl3=acid
Rank the elements or compounds in decreasing order of their boiling points 1. CH3CO2CH3 2. CH3CONHCH3 3. N2O 4. F2
CH3CONHCH3, CH3CO2CH3, N2O, F2
Identify and label the species in each reaction CN^- (aq) + H2O (l) ----> HCN (aq) + OH^- (aq)
CN^- = base H2O=acid HCN=conjugate acid OH^-=conjugate base
What is salt hydrolysis?
Cations or anions of a dissociated salt remove hydrogen ions from or donate hydrogen ions to water
Calculate standard cell potential for the reaction and indicate if the process is spontaneous 2Fe^2+ (aq) + Pb^2+ (aq) ---> 2Fe^2+ (aq) + Pb (s) Cathode: -0.77 Anode: 0.13
Cell potential: -0.90 V Not spontaneous because the above value is negative
What is the charges species consisting of a central metal cation bonded to 2 or more anions or polar molecules?
Complexion
What is a weak conjugate acid?
Conjugate acid of a strong base. Doesn't react with water
What is a strong conjugate acid?
Conjugate acid of a weak base. Acts as a weak Bronsted in water
What is a weak conjugate base?
Conjugate base of a strong acid. Doesn't react with water
What is a strong conjugate base?
Conjugate base of a weak acid. Acts as weak Bonsted acid in water
What is a zeroth order reaction?
Constant, independent of reaction concentration
Shifting equilibrium to the left does what?
Consumes what is to the right, assuming H3O^+ is on the right it will be consumed as well. This increases pH
This is a carboxylic acid A) HClO4 B) CH3OH C) CH4NH2 D) CH3COOH E) H2SO4
D
Which is not a factor in determining acid strength? A) polarity of H-X bond B) Number of oxygens in oxyacids C) Oxidation number of central atom of oxyacids D) solubility in water E) electronegativity of central atom in oxyacid
D
What is the relationship between Delta G standard and K?
Delta G standard = - RT ln K
What is the relationship between Delta G and Delta G standard?
Delta G=Delta G standard + RT ln Q R=8.314 J/K * mol or 8.314 * 10^-1 kJ/K*mol T=Kelvin Q= reaction quotient
Calculate Delta H standard, Delta S standard and Delta G standard for 2SO2 (g) + O2 (g) ---> 2SO3 (g) at 25 degrees C
Delta H - 197.8 kJ Delta S=-187.95 J/K Delta G= -141.8 kJ
The molar heats of fusion and vaporization of benzene are 10.9 and 31.0 kJ/mol respectively. Calculate entropy changes for the solid to liquid and liquid to vapor transitions for benzene. At 1 atm benzene melts at 5.5 degrees C and boils at 80.1 degrees C
Delta S fusion=39.1 J/K * mol Delta S vapor=87.7 J/K * mol
What is the change in entropy of surroundings equation?
Delta S surroundings= -Delta H system / T Delta H=enthalpy change in the system T= temperature in Kelvin
What is the change in entropy equation?
Delta S system = Sfinal - Sinitial Delta S= change in entropy of a system Sfinal=final entropy Sinitial=initial entropy
For a gaseous process involving a volume change, the change in entropy equation is
Delta S system = nR ln V final/ V initial Delta S system= Entropy change of the system n=number of moles R=gas constant V final=volume final V initial=volume initial
What is the entropy change in the universe equation?
Delta S universe = Delta S system + Delta S surroundings
What is the boiling point elevation equation?
Delta Tb=Kbm
For the reaction A2 + 3B2 ---> 2AB3, the rate of disappearance of the product can be represented as
Delta [AB3]/2 delta t
The units of the rate constant
Depend on overall reaction order
What is qualitative analysis?
Determination of the types of ions present in solution
What is the stability of any nucleus?
Difference between Columbia repulsion and the short range attraction
What is overvoltage?
Difference between the electrode potential and the actual voltage required to cause electrolysis
What is osmosis?
Diffusion of water through a selectively permeable membrane
What does dissolution mean?
Dissolving
A process that occurs spontaneously in one direction:
Does not in the other
What is a non spontaneous process?
Does not occur under a specific set of conditions
What is an equilibrium process?
Doesn't occur spontaneously in either direction but occurs with the increase or decrease of energy from a system at equilibrium
For which of the following is an ICE table required to calculate pH? A) HNO3 B) H2SO4 C) Sr (OH)2 D) NaOH E) CH3NH2
E
Which statement about an enzyme is not true? A) can alter shape to accommodate target B) biological catalysts C) Number in the thousands within living cells D) Act as substrates E) Typically small ionic compounds
E
What is Einstein's equation?
E=mc^2
How can the equation that relates K to standard reduction potential be simplified under standard conditions?
E_cell^°=(0.0592 V)/n log K
What is the equation that relates K to Standard reduction potential of a cell?
E_cell^°=RT/nF ln K
What is the Nernst equation?
Ecell = (E0cell) -RT/nF (lnQ)
What is vibrational energy?
Energy associated w/ the movement of molecules, they are always moving (remember, movement stops only at absolute zero)
What is the first law of thermodynamics?
Energy cannot be created or destroyed
What is endothermic?
Energy is absorbed
What is exothermic?
Energy is released
What is ΔE?
Energy of product - energy of reactant
What is nuclear binding energy?
Energy required to break nucleus of atom into is component parts
What is the equation for standard reduction potential of a cell
Eocell=Eocathode−Eoanode
What is Kp?
Equilibrium constant in terms of pressure
What is the formation constant?
Equilibrium constant that indicates to what extent complex-ion formation reactions occur, Kf (larger it is the more stable)
Dissolution tends to be encouraged when it is ___ and discouraged when it is ____
Exothermic, endothermic
What is reaction order?
Experimentally determined exponent of the concentration of a species in a rate law
What is the name of the expression In [A]t / [A]0 = -kt?
First order integrated rate law
Calculate concentrations of H2SO4-, SO4^2- and H3O ^+ ions in an 0.14 M sulfuric acid solution at 25 degrees C
First=0 Second=0.13 M Third=0.011 M Last=0.15 M
Calculate concentrations of H2C2O4, HC2O4-, C2O4^2- and H3O^+ ions in a 0.20 oxalic acid solution at 25 degrees C
First=0.11 M Second=0.086 M Third=6.1 * 10^-5 Last=0.086 M
What is a breeder reactor?
Fission reactor that turns non-fissionable isotopes into fissionable isotopes
What are dipole-dipole forces?
Forces of attraction between polar molecules
What are ion-ion forces?
Forces that exist between ions
What causes higher entropy?
Free-ranging and mobile particles
Order the freezing point and boiling points of each substance A) 4.5 g of CaCl2 in 200 mL of water B) 4.5 g of C3H8O2 in 200 mL of water C) 4.5 g of NaCl in 200 mL of water D) 200 mL of pure water
Freezing points= C, A, B, D Boiling points= D, B, A, C
When the solute and solvent are gas what is the state of the resulting solution?
Gas
For a given substance what is relationship that entropy shares with each of the three states of matter?
Gas has the greatest entropy, liquid has the second greatest entropy and solid has the least entropy
What is a thermonuclear reaction?
Generally refers to a fusion reaction
A mix of 5.75 atm of H2 and 5.75 atm of I2 is contained in a 1.0 L vessel at 430 degrees C. The equilibrium constant Kp for the reaction: H2 (g) + I2 (g) ------><-----2HI (g) at this temp is 54.3. Determine the equilibrium partial pressures of H2, I2 and HI
H2 and I2 = 1.23 atm HI=9.04
We have a conjugate acid that has the formula H3BO3 and a Ka value of 5.8 * 10^-10. What is the formula and kb value of the conjugate base?
H2BO3^-, 1.7 * 10^-5
What species is a Bronsted acid? H2CO3 (aq) + H2O (l) ---> HCO3- (aq) + H3O^+ (aq)
H2CO3
Carbonic acid is a polyprotic acid. Write the balanced chemical equation for the sequence of reactions that carbonic acid can undergo when it's dissolved in water
H2CO3 (aq) + H2O (l) ---> H3O ^+ (aq) + HCO3^- (aq) HCO3^- (aq) + H2O (l) ----> H3O^+ (aq) + CO3^2- (aq)
Use half reaction method to balance the following equation in basic solution: CN- + MnO4- ---> CNO- + MnO2
H2O + 3CN- + 2MnO4- ---> 3CNO- + 2MnO2 + 2OH-
Enter the chemical formula of a binary molecular compound of hydrogen and a group 6A element that can be reasonably expected to be less acidic in aqueous solution than H2Se.
H2S
H2SO3 or H2CO3. Which is more acidic?
H2SO3
H2SeO3 or H2SO3. Which is more acidic?
H2SO3
HSO3^- is the conjugate base of what species?
H2SO3
Which is the stronger acid HSO3^- or H2SO3?
H2SO3
H2SeO4 or H2SO4. Which is stronger?
H2SO4
Sulfuric acid
H2SO4
Sulfuric acid. What's the formula? Ionic or molecular? Strong or weak acid/base?
H2SO4. Molecular and strong acid
Enter the chemical formula of a binary molecular compound of hydrogen and a group 6A element that can be reasonably expected to be more acidic in aqueous solution than H2S.
H2Se
H2SeO4 or H2SeO3. Which is more acidic?
H2SeO4
H2TeO4 or H2TeO3. Which is more acidic?
H2TeO4
Which is the stronger acid? H3AsO4 or H3AsO3?
H3AsO4
What is the conjugate acid of H2O?
H3O+
What is the conjugate acid of H2PO4^-?
H3PO4
Enter the chemical formula of a binary molecular compound of hydrogen and a group 7A element that can be reasonably be expected to be less acidic in aqueous solution than HI
HBr
Hydrobromic acid
HBr
HBrO3 or HBrO4. Which is stronger?
HBrO4
What is the conjugate base of H2C2O4?
HC2O4^-
Acetic acid. What's the formula? Ionic or molecular? Strong or weak acid/base?
HCH3CO2, molecular and weak acid
When using molality the correct units are
Mole soute/kg solvent
What is rotational energy?
Molecules spin in known "orbits"
What is a mole fraction (weird X)?
Moles of a single component/total number of moles
Ph of a buffer cannot be
More than 1 pH unit different from the pKa
What is translational energy?
Movement of molecules through space
Silver nitrate is added slowly to a solution that is 0.020 M in Cl^- ions and 0.020 M in Br^- ions. Calculate the concentration in Ag^+ ions (in M) required to initiate the precipitation of AgBr without precipitating AgCl
Must be greater than 3.9 * 10^-11 and less than 8.0 * 10^-9 M
Ammonia. What's the formula? Is it ionic or molecular? Strong or weak acid/base?
NH3. Molecular and weak base
What is the conjugate acid of NH3?
NH4+
Identify and label species NH4^+ (aq) + H2O (l) ---> NH3 (aq) + H3O^+ (aq)
NH4^+=acid H2O=base NH3=conjugate base H3O^+=conjugate base
Sodium chlorate. What's the formula? Ionic or molecular? Strong or weak acid/base?
NaClO3. Ionic
What does a constant that falls between 1*10^2 and 1*10^-2 indicate?
Neither reactants or products are strongly favored
Determine if KNO3 is acidic, basic or neutral
Neutral
Is SrBr2 basic, acidic or neutral?
Neutral
An aqueous solution of KNO3 is ____ because ____
Neutral, neither ion hydrolyzes in water
Q is less than Ksp
No precipitate will form
1. Delta G standard < 0 2. K > 1 3. ln K > 0 4. Delta H standard < T delta S standard Which statement is false if any?
None
1. ln K = 0 2. Delta H standard = T delta S standard 3. Delta G = 0 4. K = 1 Which statement is false, if any?
None
To compare the stability of two nuclei:
Nuclear binding energy = nuclear binding energy / number of nucleons
If repulsion outweighs attraction
Nucleus disintegrates emitting particles and or radion
A current of 1.26 A is passed through an electrolytic cell containing a dilute sulfuric acid solution for 7.44 h. Write the half cell reactions and calculate the volume of gases generated at STP
O2=1.96 L H2=3.92 L
What is an ion-dipole force?
Occurs between ions and polar molecules
What is a spontaneous process?
Occurs under a specific set of conditions
What is a saturated solution?
One that contains as much solute as the solvent can hold at a given temperature
What is a non volatile solute?
One that does not exert vapor pressure
What metals typically don't impact pH?
Ones in Groups 1A and 2A
What anions typically don't impact pH?
Ones that are conjugate bases of strong acids
What is Raoult's Law equation?
P1 = X1Pdegrees1
The equation for vapor pressure of a solution is
PA=XaP^degree A
Which is the stronger acid? NH3 or PH3?
PH3
Write the pressure equilibrium constant expression for this reaction 2CH3OH (l) + 3O2 (g) ------> 2CO2 (g) + 4H2O (g)
P^2CO2 P^4H2O / P^3O2
What is Dalton's Law of Partial Pressures?
Partial pressure = total pressure * fractional gas concentration
In a solution with only one solute what is Raoult's law equation rewritten as?
Pdegrees1 - P1 = delta P = X2Pdegrees1
What is percent dissociation?
Percentage of dissolved molecules that separate into ions in solution
HClO4. What's the name? Ionic or molecular? Strong or weak acid/base?
Perchloric acid, molecular and strong acid
Calculate solubility at 25 degrees C of Co(OH)2 in pure water and in a 0.0150 M CoCl2 solution. Ksp=5.92 * 10^-15
Pure water: 0.011 Solution: 2.9 * 10^-5
Calculate solubility at 25 degrees C of CaF2 in pure water and in 0.0150 M NaF. Ksp=3.45 * 10^-11
Pure water: 0.016 g/L Solution: 1.2 * 10^-5 g/L
Calculate solubility at 25 degrees C of PbCO3 in pure water and in a 0.0150 M Pb(NO3)2 solution. Ksp=7.40 * 10^-14. Round to 2 decimal places
Pure water: 7.4 * 10^-5 g/L Solution: 1.3 * 10^-9 g/L
A student prepares a solution of NH3 and adds bromcresol purple. What color is the solution?
Purple
What is the law of mass action?
Qc = [C][D]/[A][B] = Kc
Systems tend to change to new configurations that ___ the system entropy
Increase
What will change the volume of the equilibrium constant?
Increasing or decreasing reaction temperature
The labels on an ICE table are
Initial, change, equilibrium
A solution initially contains H2O and HCl. What is the initial type? If I were to add KCl what would the change in pH be?
Initially acidic, ends up being the same because pH doesn't change
A solution initially contains H2O and HCl. What is the initial type? If I were to add KOH what would the change in pH be?
Initially acidic, ends up having pH go up
A solution initially has H2O. What is the initial type? If I were to add NaNO3 what would the effect be on pH?
Initially basic, ends up being the same because pH doesn't change
A solution initially has KOH and H2O. What is the initial type? If I were to add KI what would the effect on pH be?
Initially basic, ends up being the same because pH doesn't change
A solution initially has KOH and H2O. What is the initial type? If I were to add HI what would the effect on pH be?
Initially basic, ends up having pH go down
A solution initially contains H2O. What is the initial type? If I were to add NaBr what would the change in pH be?
Initially neutral, ends up being the same because pH doesn't change
A solution initially contains H2O. What is the initial type? If I were to add NaOH what would the change in pH be?
Initially neutral, ends up having pH go up
A solution initially contains H2O. What is the initial type? If I were to add NaOH what would the effect on pH be?
Initially starts neutral, ends up having pH go up
Why do solutions form?
Intermolecular forces and solubility
KClO4. What's the name? Ionic or molecular? Strong or weak acid/base?
Ionic
What are the things to remember about equilibrium?
It is a dynamic state in which both forward and reverse reactions continue to occur, the rates of both those reactions are equal, can be established with only reactants, only products or a mix of both,
The Haber process, which is used industrially to generate NH3--largely for the production of fertilizers-- is represented by: N2 (g) + 3H2 (g) -----><------- 2NH3 (g) Delta H rxn [NH3 (g) ] =-46.3 kJ/mol Indicate what direction equilibrium will shift if temperature is increased. What direction will it go if temperature is decreased
It is exothermic so it will shift left if the temperature increases and right if it goes down
What is the advantage of molarity?
It is generally easy to measure the volume of a solution than to weigh the solvent
How can you tell if a salt is neutral?
It is made of the cation of a strong base and the anion of a strong acid
At 375 degrees C, the equilibrium constant for the reaction N2 (g) + 3H2 (g) ----><------ 2NH3 (g) is 1.2. At the start of the reaction, the concentration of N2, H2, and NH3 are 0.071 M, 9.2 * 10^-3 M, and 1.83 * 10^-4 M. Determine whether this system is at equilibrium and if not, determine which direction its going
It is not at equilibrium and must proceed to the right to establish it
Predict whether the following reaction will occur spontaneously as written at 298 K: Co (s) + Fe^2+ (aq) ---> Co^2+ (aq) + Fe(s) Assuming [CO^2+]=0.15 M and [Fe^2+]=0.68 M Standard reduction potentials are: Cathode: -0.44 V Anode: -0.28 V
It is not spontaneous under the conditions described, indicated by the negative E value
What is the advantage of molality?
It is temperature independent
What is the advantage of percent by mass?
It is temperature independent and the molar mass of the solute does not need to be known
What is the rule with any atomic number over 83?
It's unstable
Potassium chloride. What's the formula? Ionic or molecular? Strong or weak acid/base?
KCl, ionic
What is the base ionization constant?
Kb
Fill in the left side of the equilibrium constant equation for the reaction of pyridine with water?
Kb= [C3H5NH^+][OH^-]/ [C5H5N]
What is the equilibrium constant expression?
Kc = [products]/[reactants]
What is the equilibrium expression for heterogenous equilibrium?
Kc* = [X]^x / [Y]^y
Write the equilibrium constant expression for: Fe2O3 (s) + 3CO (g) ----> 2Fe (s) + 3CO2 (g)
Kc=[CO2)^3/[CO]^3
Consider the following chemical equilibrium: H2 (g) + F2 (g) ----> 2HF (g) Now write an equation that shows how to calculate Kc from kp for this reaction at an absolute temperature. You can assume it is comfortable above room temperature
Kc=kp
consider the following chemical equilibrium: 2H2 (g) + O2 (g) -----> 2H2O (l) Now write an equation below that shows how to calculate kc from kp for this reaction at absolute temperature. You can assume T is comfortable above room temperature
Kc=kp(RT)^3
What is the solubility product constant?
Ksp
Complete the following solubility constant expression for Ag2CO3
Ksp=[Ag^+]^2 [CO3^2-]
What does Ka * Kb equal?
Kw
What does an equilibrium constant with a magnitude greater than 1*10^2 indicate?
Large
What are the strong bases?
LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
When the solute and solvent are liquid what is the state of the resulting solution?
Liquid
When the solute is gas and the solvent is liquid what is the state of the resulting solution?
Liquid
When the solute is solid and the solvent is liquid what is the state of the resulting solution?
Liquid
What happens to the Henderson-Hasselbalch when the concentration of the weak acid equals that of the conjugate base
Log term is 0 and the pH is numerally equal to pKa
What is the number on top mean?
Mass number (total number of neutrons and protons)
What is delta Δm?
Mass of product-mass of reactants
What are moderators?
Material that limits speed of liberated neutrons but does not itself undergo fission when bombarded with neutrons. Should be nontoxic and inexpensive and it should resist conversion into a radioactive substance by neutron bombardment. It is also preferably liquid
Balance the following redox reaction in basic solution: MnO2 (s) + Fe^3+ (aq) ---> MnO4- (aq) + Fe^2+ (aq)
MnO2 (s) + 4OH- (aq) + 3Fe^3+ (aq) ---> MnO4- (aq) + 2H2O (l) +3Fe^2+ (aq)
Write a balanced half reaction for the oxidation of manganese ion (Mn^2+) to solid manganese dioxide (MnO2) in acidic aqueous solution. Be sure to add physical state symbols where appropriate
Mn^2+ (aq) + 2H2O (l) ---> MnO2 (s) + 4H^+ (aq) + 2e-
Write a balanced half reaction for the oxidation of manganese ion (Mn^2+) to permanganate ion (MnO4-) in basic aqueous solution. Be sure to add physical state symbols where appropriate
Mn^2+ (aq) + 8OH- (aq) ---> MnO4- (aq) + 4H2O (l) + 5e-
A tiny sample of an aqueous solution of two substances R and P is sketched below, as if it's under an imaginary microscope so powerful that individual molecules can be seen R=1 P=11 R and P can interconvert. That is, R can turn into P and P can turn back into R. K=11. The equilibrium constant K for this expression is 11. Predict the number of R and P molecules in this sample when the interconversion reaches equilibrium
R=1 P=11
A tiny sample of an aqueous solution of two substances R and P is sketched below, as if it's under an imaginary microscope so powerful that individual molecules can be seen. R=7 P=3 R and P can interconvert. K=1. Predict the number of R and P molecules in this sample when the interconversion reaches equilibrium
R=5 P=5
A tiny sample of an aqueous solution of two substances R and P is sketched below, as if it's under an imaginary microscope so powerful that individual molecules can be seen. R=3 P=7 R and P can interconvert. K=1/4. Predict the number of R and P molecules when the interconversions reach equilibrium
R=8 P=2
A reaction that is second order in A and zero order in B has the rate law
Rate=k[A]^2
What does a negative standard reduction potential mean?
Reactants will be favored at equilibrium
Tiny samples of aqueous solution are sketched below as if under a microscope so powerful that individual molecules can be seen. The two substances in each sample can interconvert. That is, each kind can turn into the other. The equilibrium constant K for each interconversion equilibrium is shown below the sketch. Decide whether each is at equilibrium Reaction 1 [R]=1 [P]=11 K=11 Reaction 2 [R]=8 [P]=4 K=1/2 Reaction 3 [R]= 10 [P]= 2 K=1/5
Reaction 1= yes Reaction 2=yes Reaction 3=yes
What does an equilibrium constant magnitude smaller than 1*10^-2 indicate?
Small
What does Henry's Law state?
That the amount of gas that dissolves in a liquid is proportional to the partial pressure of the gas in the gas phase
What is activation energy (Ea)?
The amount of energy that reactants must absorb before a chemical reaction will start; also called free energy of activation
What is solubility?
The amount of solute dissolved in a given volume of a saturated solution
In determining the pH of a buffer, what rule is used?
The approximation rule
What is an ion-induced dipole?
The charge of an ion induces a temporary partial charge on a neighboring nonpolar molecule or ion
What does [A]t mean?
The molar concentration of A at any given time during the reaction
The greater the nuclear binding energy per nucleon
The more stable the nucleus
If attraction forces prevail
The nucleus is stable
For 2 monoatomic species which one has the larger entropy?
The one with the greatest molar mass
For 2 substances in the same phase and with similar molar masses, which has the greatest entropy?
The one with the more complex chemical structure
In a case where an element exists in 2 or more allotropic forms. Which has the greater entropy?
The one with the more mobile atoms
What are dispersion forces?
The phenomenon that occurs when electrons within an element or a compound concentrate themselves on the end of an atom. They occur in all molecules
What is the second law of thermodynamics?
The principle stating that every energy transfer or transformation increases the entropy of the universe
What is hydration?
The process in which an ion is surrounded by water molecules arranged in a specific manner
What is solvation?
The process of surrounding solute particles with solvent particles to form a solution
What is galvanization?
The process that protects iron-based materials from rust by coating them with zinc
As the atomic number increases
The ratio becomes less ideal and the neutrons increase and nucleus becomes unstable
What does it mean when Q>K?
The ratio of initial concentrations of products to reactants is too large. To reach equilibrium, products must be converted to reactants. The system proceeds in the reverse direction
What does it mean when Q<K
The ratio of initial concentrations of products:reactants is too small. To reach equilibrium, reactants must be converted to products. The system proceeds in the forward direction
A linear plot of In[A] vs t means
The reaction follows first order kinetics
The reaction 2HBr (aq) -----> H2 (g) + Br2 (g) has a Kc value of 7.1 * 10^4 at a particular temperature. What does this value indicate?
The reaction mixture contains mostly products
What happens if the volume is decreased at constant temperature? N2 (g) + 3H2 (g) ----> 2NH3 (g)
The reaction will shift right producing more ammonia
What is the Tyndall effect?
The scattering of light by colloidal particles
What is fractional precipitation?
The separation of a mixture based upon the components' solubilities.
What is a reaction mechanism?
The series of elementary reactions or steps that take place during the course of a complex reaction
What is the common ion effect?
The solubility of a salt is considerably reduced when it is dissolved in a solution that already contains one of its constituent ions as compared to its solubility in a pure solvent
What is nuclear fission?
The splitting of an atomic nucleus
What is collision theory?
The theory that chemical reactions only occur when particles collide with sufficient energy
What happens if the volume is increased at constant temperature? CO2 (g) + H2 (g) ----> CO (g) + H2O (g)
There be no shifting, same number of moles on both sides
Equation for number of possible arrangements
W=X^n W=number of possible arrangements X=number of possible locations of molecules n=number of molecules in the system
What is the autoionization of water?
Water acting as acid and base, giving us Kw where Kw=[H+][OH-] and Kw=1*10^-14
What does hydrophobic mean?
Water fearing
What are weak acids?
Weak acids are acids that partially ionise in aqueous solutions
What is a dipole-induced dipole?
When a polar molecule attracts the electron in a nonpolar molecule
What is Le Chatelier's principle?
When a reaction at equilibrium is changed, it will seek to counteract that change
What does the extent of hydrolysis with a metal ion and a dissolved salt depend on?
Whether or not the metal is a small and highly charged metal cation
The effect of temperature change on a system at equilibrium depends on
Whether the reaction is endothermic or exothermic
What color is a solution of pH=7 with a methyl red indicator?
Yellow
What is an elementary reaction?
a reaction in which reactants are converted to products in a single step
What is a first order reaction?
a reaction whose rate depends on the reactant concentration raised to the first power
What is a radioactive decay series?
a series of nuclear reactions that begins with an unstable nucleus and results in the formation of a stable nucleus
What is a half cell?
a single electrode immersed in a solution of its ions
What is a buffer?
a solution that resists changes in pH when acid or alkali is added to it. Buffers typically involve a weak acid or alkali together with one of its salts
What does "At equilibrium" mean?
a state in which opposing forces or influences are balanced.
What is amphoteric?
a substance that can act as both an acid and a base
Ethylene glycol is a common automobile antifreeze. It is water soluble and fairly nonvolatile (boiling point 197 degrees C). Calculate (a) the freezing point and (b) the boiling point of a solution contains 685 g of ethylene glycol in 2075 g of water
a) -9.89 degrees C b) 102.8 degrees C
A solution is made by dissolving 170.1 g of glucose (C6H12O6) in enough water to make a liter of solution. The density of the solution is 1.062 g/mL. Express the concentration of the solution is (a) molality (b) percent by mass and (c) parts per million,
a) 1.06 m B) 16.02% glucose C) 16.02 * 10^5 ppm glucose
Calculate the concentration of carbon dioxide in a soft drink that was bottled under a partial pressure of 5.0 atm CO2 at 25 degrees C (a) before the bottle is opened and (b) after the soda has gone "flat" at 25 degrees C. The Henry's Law constant for CO2 in water at this temperature is 3.1 *10^-2 mol/L*atm. Assume that the partial pressure of CO2 in air is 0.0004 atm and that Henry's Law constant for the soft drink is the same as that of water
a) 1.6*10^-1 mol/L b) 1*10^-5 mol/L
"Rubbing alcohol" is a mixture of isopropyl alcohol (C3H7OH) and water that is 70% isopropyl alcohol by mass (density= 0.79 g/mL at 20 degrees C). Express the concentration of rubbing alcohol in (a) molarity and (b) molality
a) 9.2 M b) 39 m
What is Ka?
acid dissociation constant
What is the van't Hoff factor (i)?
actual number of particles in solution after dissociation/number of formula units initially dissolved in solution
NH3. What's the name? Is it ionic or molecular? Strong or weak acid/base?
ammonia, molecular and a weak base
What is an oxyacid?
an acid that is a compound of hydrogen, oxygen, and a third element, usually a nonmetal
What is rate law?
an expression for the rate of a reaction in terms of the concentration of reactants
What is an activated complex?
an unstable arrangement of atoms that forms momentarily at the peak of the activation-energy barrier
What is kb?
base dissociation constant
Is KClO basic, acidic or neutral?
basic
Above the belt of stability
beta emission
Given that the parent nuclide in 8/3 Li and the daughter nuclide is 8/4 Be what is the decay mode?
beta emission
Given that the parent nuclide is 3/1 H and the daughter nuclide is 3/2 He what is the decay mode?
beta emission
What does isotonic mean?
both solutions have an equal concentration and the same osmotic pressure
What is Henry's Law equation?
c=kP
HClO3
chloric acid
What are intermediates?
compounds that form between an initial reactant and a final product
What are the units of Kf in the freezing point depression equation?
degrees C/m
What are the units of Kb in the boiling point elevation equation?
degrees C/m or degrees C kg/mol
What is the enthalpy change for the solution process given by?
delta Hsoln = delta H1 + delta H2 + delta H3
Write a balanced half reaction for the reduction of nitrate ion (NO3-) to gaseous nitrogen dioxide in basic aqueous solution. be sure to add physical state symbols where appropriate
e- + H2O (l) + NO3- (aq) ---> NO2 (g) + 2OH- (aq)
What is a Lewis acid?
electron pair acceptor
What is a Lewis base?
electron pair donor
What is a transuranium element?
elements having more than 92 protons, all of which are synthetic and unstable
Titration of strong acid and weak base
equivalence point pH < 7
What is the standard free energy of reaction?
free-energy change for a reaction when it occurs under standard-state conditions
What two colligative properties of non electrolyte solutions provide the means of determining the molar mass of a solute?
freezing point depression and osmotic pressure
What is nuclear fusion?
The joining (fusing) of small nuclei.
What is pH?
measure of hydrogen ion concentration
Ammonia has been studied as an alternative "clean" fuel for internal combustion engines, since its reaction with oxygen produces only nitrogen and water vapor, and in the liquid form it is easily transported. An industrial chemist studying this reaction fills a 50.0 L tank with 4.1 mol of ammonia gas and 3.2 mol of oxygen gas, and when the mixture comes to equilibrium the amount of nitrogen gas is 0.21 mol. Calculate the concentration equilibrium constant for the combustion of ammonia at the final temperature of the mixture. Round to 2 sig figs
1.3 * 10^-8
The atomic mass of 127/53 I is 126.904473 amu. Calculate nuclear binding energy of this nucleus and the corresponding nuclear binding energy per nucleon
1.35313 * 10^-12 J/nucleon
In the presence aqueous CN, cadmium (II) forms the complex ion Cd(CN)4^2-. Determine molar concentration of free (uncompleted) cadmium (II) ion in solution when 0.20 mol of Cd(NO3)2 is dissolved in a L of 2.0 M NaCN
1.4 * 10^-18
A 0.025 M solution of latic acid, HC3H5O3, has a pH of 2.75. Calculate Ka and the percent ionization of lactic acid.
1.4 * 10^-4, 7.1%
Determine the Kb of a weak base if a 0.35 M solution of the base has a pH of 11.84 at 25 degrees C
1.4 * 10^4
A galvanic cell at a temperature of 25.0 degrees C is powered by the following redox reaction: 2IO3- (aq) + 12H+ (aq) + 5Co (s) ---> I2 (s) + 6H2O (l) + 5CO^2+ (aq) Suppose a cell is prepared with 0.417 M IO3- and 2.70 M H+ in one half cell and 5.09 M Co^2_ in the other. Calculate cell voltage under these conditions. Round to 3 sig figs
1.48 V
An aqueous solution at 25 degrees C has a OH^- concentration of 1.1 * 10^-9 M. Calculate the H3O ^+ concentration
1.5 * 10^-9 M
0.010 mol N2O4 is placed in a 2.0 L flask. At equilibrium [N2O4] is 0.0042 M. Calculate Kc
1.6 * 10^-3
Calculate solubility of copper (l) hydroxide in g/L
1.7 * 10^-5
Calculate the rate constant at 200 degrees C for the reaction that has a rate constant of 8.1*10^-4 s^-1 at 90 degrees and an activation energy of 99 kJ/mol
1.7/s
When 110 g of benzamide are dissolved in 800 g of a certain mystery liquid X the freezing point of the solution is 6.6 degrees C lower than the freezing point of pure X. On the other hand, when 110 g of ammonium chloride is dissolved in the same mass of X, the freezing point of the solution is 27.4 degrees C lower than the freezing point of pure X. Calculate the van't Hoff factor for ammonium chloride in X,
1.8
The pH of a 0.23 M of acetic acid is measured to be 2.69. Calculate Ka
1.8 * 10^-5
Carbon dioxide and water react to form methanol and oxygen, like this: 2CO2 (g) + 4H2O (g) ----> 2CH3OH (l) + 3O2 (g) At a certain temperature, a chemist finds that a 2.5 L reaction vessel constraining a mixture of carbon dioxide, water, ethanol and oxygen at equilibrium has the following composition. CO2=4.75 g H2O= 2.53 g CH3OH=2.73 g O2=2.58 g Calculate the value of equilibrium constant Kc for this reaction. Round your answer to 2 significant figures
1.8 * 10^3
Consider this reaction: 2HI (g) ----> H2 (g) + I2 (g) At a certain temperature it obeys this rate law rate= (3.28 M^-1*s^-1)[HI]^2 Suppose a vessel contains HI at a concentration of 0.720 M. Calculate how long it takes for the concentration to decrease by 81.0%. You may assume that no other reaction is important. Round to 2 sig figs
1.8 s
A solution is prepare at 25 degrees C that is initially 0.45 M in (HClO2) a weak base with Ka=1.1 * 10^-2, and 0.36 M in KClO2. Calculate pH of solution to 2 decimal places
1.85
Calculate Ka of weak acid if 0.065 M solution of the acid has a pH of 2.96 at 25 degrees C
1.9 * 10^5
The osmotic pressure of 0.0100 M potassium iodide (KI) solution at 25 degrees C is 0.465 atm. Determine the experimental van't Hoff factor for KI at this concentration
1.90
A rock is found to contain 5.51 mg of Uranium-238 and 1.63 mg of Terbium 206. Determine the age of the rock. Half life of Uranium 238 is 4.51 * 10^9 years
1.91 * 10^9 years
Consider the reaction Br2(aq) + HCOOH (aq) ----> 2Br(aq) + 2H^+ (aq) + CO2 (g) Calculate the average rate of disappearance of Br2 from 200 to 250 s Time Molarity M/s 200. 0.00596 2.09 * 10^-5 250. 0.00500. 1.75 * 10^-5
1.92 * 10^-5 M/s
A certain reaction is second order in N2 and first order in H2. Use this information to complete the table below [N2]. [H2]. Initial rate of reaction 0.559 M 0.813 M. 4.00*10^4 M/s 0.559 M 0.813 M. 4.00*10^4 M/s 0.559 M. 3.98 M. ? M/s 0.836 M. 0.544 M. ? M/s
1.96 * 10^5 M/s and 5.99*10^4 M/s
A galvanic cell consists of an Mg electrode in a 1.0 M Mg(NO3)2 solution and a Cd electrode in a 1.0 M Cd(NO3)2 solution. Determine overall cell reaction and calculate the standard cell potential at 25 degrees C
1.97 V
What is the equilibrium constant expression for the reaction: O2 (g) + 2H2 (g) ---> 2H2O (l)
1/ PH2P2O2
Fill in the missing symbol in the nuclear chemical equation 238/92 U + ? ----> 239/92 U?
1/0 n
What is the symbol for a neutron?
1/0 n
What is the symbol for a proton?
1/1 p or 1/1 H
Solve for x log10x=-1
1/10
What is the integrated second order rate law?
1/[A] - 1/[A]o = kt
If the hydronium concentration is 8.4 * 10^-11. What is the pH?
10.08
The base protonation constant Kb of azetidine is 1.5 * 10^-8. Calculate pH of a 1.3 M solution at 25 degrees C. Round to 1 decimal place
10.2
The concentration of hydroxide ions in antacid milk of magnesia is 5.0 * 10^-4 M. Calculate hydronium ions at 25 degrees C.
2.0 * 10^-11 M
The rate constant of a certain reaction is known to obey the Arrhenius equation and to have an activation energy of Ea = 18.0 kJ/mol. If the rate constant of this reaction is 1.6*10^7 M^-1 * s^-1 at 63.0 degrees C. What will the rate constant be at -19.0 degrees C. Round to 2 sig figs
2.0 * 10^6 M^-1 * s^-1
A 500.00 mL sample of pure water is allowed to come to equilibrium with pure oxygen gas a pressure of 755 mmHg. What mass of oxygen dissolves in water?
2.1 * 10^-2 g
Suppose a 250 mL flask is filled with 1.2 mol H2 and 1.0 mol HCl. The following reaction becomes possible: H2 (g) + Cl2 (g) -----> 2HCl (g) The equilibrium constant K for this reaction is 0.954 at the temperature of the flask. Calculate equilibrium molarity of HCl. Round to two decimal places
2.21 M
3.607 g - 1.40 g
2.21 g
The acid dissociation constant Ka of acetic acid is 1.8 * 10^-5. Calculate pH of a 1.7 M solution. Round to 1 decimal place
2.3
The acid dissociation constant Ka of trimethylacetic acid is 9.33 * 10^-6. Calculate pH of a 1.9 M solution. Round to 1 decimal place
2.4
The solubility of CaSO4 is measured experimentally and found to be 0.067 g/L. Calculate value of Ksp
2.4 * 10^-5
Calculate molar solubility of silver chloride in a solution that is 6.5 * 10^-3 M in silver nitrate
2.5 * 10^-8 M
Calculate standard free energy change for the following reaction at 25 degrees C: 2Au (s) + 3Ca^2+ (1.0 M) ---> 2Au^3+ (1.0 M) + 3Ca(s) The standard reduction potential values are: Cathode: -2.87 V Anode: 1.50 V
2.53 * 10^3 kJ/mol
The rate of decomposition of azomethane is studied by monitoring the partial pressure of the reactant as a function of time CH3-N triple bond N-CH3(g) ----> N2(g) + C2H6 (g) The data obtained at 300 degrees C are listed below Time (s). mmHg 0. 284 100. 220 150. 193 200. 170 250. 150 300. 132 Determine the rate constant of the reaction at this temperature
2.55*10^-3 s^-1
A certain reaction is second order in N2 and first order in H2. Use this information to complete the table below [N2]. [H2]. Initial rate of reaction 1.19 M 0.559 M. 1.00*10^4 M/s 1.19 M. 0.150 M. ? M/s 1.52 M. 0.437 M. ? M/s
2.68*10^3 M/s and 1.28 * 1064 M/s
Calculate the half life of azomethane given that k=2.55*10^-3 s^-1 at 300 degrees C
2.72*10^2 s
A galvanic cell at a temperature of 25 degrees C is powered by the following redox reaction: Sn^2+ (aq) + Ba(s) ---> Sn(s) + Ba^2+ (aq) Suppose the cell is prepared with 5.89 M Sn^2+ in one half cell and 1.64 M Ba^2+ in the other. Calculate cell voltage made under these conditions. Round to 3 sig figs
2.78 V
The value of Kw at normal body temperature (37 degrees C) is 2.8 * 10^-14. Calculate concentration of hydroxide ions in stomach acid at body temperature. [H3O^+]=0.10 M
2.8 * 10^-13
428 mg of an unknown protein is dissolved in enough solvent to make 5.00 mL of solution. The osmotic pressure of the solution is measured to be 0.0731 atm at 25.0 degrees C. Calculate molar mass of protein
2.86 * 10^4 g/mol
Calculate pH at 25 degrees C of a 0.18 M solution of a weak acid that has Ka=9.2 * 10^-6
2.89
The acid dissociation constant of carbonic acid is 4.5 * 10^07. Calculate pH of 2.8 M solution. Round to 1 decimal place
2.9
Determine the pH of a solution of a 0.25 solution of Pyridium nitrate at 25 degrees C
2.92
Suppose a hydrogen 2 nuclide transforms into helium 3 by absorbing a proton. Complete the nuclear chemical equation below so that it describes the nuclear reaction ----> 3/2 He
2/1 H + 1/1 H
The decomposition of ethane (C2H6) to methyl radicals CH3 is a first order reaction with a rate constant of 5.36*10^-4 s^-1 at 700 degrees C C2H6---> 2CH3 Calculate the half life of the reaction in minutes
21.5 min
Calculate vapor pressure of a solution made by dissolve 115 g urea (NH2)2 CO in 485 g water at 25 degrees C. (The molar mass of urea is 60.06 g/mol and the P degree H2O=23.8 mmHg),
22.2 mmHg
The rate of a certain reaction is given by the following rate law: rate=k[N2][H2]^2 Use this information to answer the questions: A) What is the reaction order in N2? B) What is the reaction order in H2? C) What is the overall order of the reaction? D) At a certain concentration of N2 and H2 the initial rate of reaction is 3.0*10^5 M/s. What would the initial rate of reaction be if the concentration of N2 were doubled? E) the rate of reaction is measured to be 80.0 M/s when [N2]=0.85 M and [H2]=0.43 M. Calculate value of rate constant
A) 1 B) 2 C) 3 D) 6.0*10^5 M/s E) 5.1*10^2 M^-2 * s^-1
Consider the following data on some weak acids and weak bases: Nitrous acid, HNO2, Ka=4.5 * 10^-4 Acetic acid, HCH3CO2, Ka=1.8 * 10^-5 Hydroxylamine, HONH2, Kb=1.1 * 10^-8 aniline, C6H5NH2, Kb=4.3 * 10^-10 Use this data to rank the following solutions in order of increasing pH. 1 is the lowest, 4 is the highest A) 0.1 M C6H5NH3Br B) 0.1 M KNO3 C) 0.1 M NaCH3CO2 D) 0.1 M KNO2
A) 1 B) 2 C) 4 D) 3
A medical technician is working with 4 samples of radionuclides listed in the table below. Initially, each sample contains 20.00 micro moles of the radionuclide. First, order the samples by decreasing radioactivity. Then, calculate how long it will take for the amount of radionuclide in each sample to decrease to 1/32 of the initial amount A) 122/53 I half life=4.0 minutes B) 51/25 Mn half life=46.0 minutes C) 201/81 Tl half life=73.0 hours D) 203/82 Tb half life=2.0 days
A) 1 (highest), 20 minutes B) 2, 230 minutes C) 4 (lowest), 365 hours D) 3, 10 days
Calculate pH of an aqueous solution at 25 degrees C that is (a) 0.081 M in HI (b) 8.2 * 10^-6 M in HNO4 and (c) 5.4 * 10^-4 M in HClO4
A) 1.09 B) 5.09 C) 2.27
Determine (a) Kb of the weak base B whose conjugate acid HB^+ has Ka=8.9 * 10^-4 and (b) Ka of a weak acid Ha whose conjugate base has Kb=2.1 * 10^-8
A) 1.1 * 10^-11 B) 4.8 * 10^7
Calculate the concentration of HCl in a solution at 25 degrees C that has pH (a) 4.95 (b) 3.45 (c) 2.78
A) 1.1 * 10^-5 M B) 3.5 * 10^-4 M C) 1.7 * 10^-3 M
Calculate the hydroxide ion concentration at 25 degrees in which pOH is (a) 4.91 (b) 9.03 (c) 10.55
A) 1.2 * 10^-5 M B) 9.3 * 10^-10 M C) 2.8 * 10^-11
Iodine atoms combine to form molecular iodine in the gas phase: I (g) + I (g) ---> I2 (g) The equation can also be written as 2I(g) ---> I2(g). The reaction is second order and has a rate constant of 7.0*10^9 M^-1 * s^-1 at 23 degrees C. (a) If the initial concentration of I is 0.086 M calculate the concentration after 2.0 minutes. (b) calculate the half life of the reaction when the initial concentration of I is 0.60 M and when the initial concentration of I is 0.42 M,
A) 1.2* 10^-12 M B) 3.4*10^-10 s
Calculate hydronium concentration in a solution at 25 degrees C in which pH is (a) 9.90 (b) 1.45 (c) 7.01
A) 1.3 * 10^-10 M B) 3.5 * 10^-2 M C) 9.8 * 10^-8 M
An aqueous solution of a strong base has a pH of 8.15 at 25 degrees C. Calculate original concentration of base in the solution (a) if the base is NaOH and (b) if the base is Ba(OH)2
A) 1.4 * 10^-6 B) 1.41 * 10^-6 M
The Ksp for PbI2 is 1.4 * 10^-. Calculate solubility in A) Pure water B) 0.10 M Pb(NO3)2 C) 0.10 M NaI
A) 1.4 * 10^-8 B) 1.9 * 10^-4 C) 1.4 * 10^-6
Calculate the pH of an aqueous solution at 25 degrees C that is (a) 0.0035 M in HF (b) 1.2 * 10^-4 M in HNO3, and (c) 6.7 * 10^-5 M in HClO4
A) 1.46 B) 3.92 C) 4.17
Determine (a) Kb of C6H5COO^- (b) Kb of HC6H6O6- and (c) Ka of C2H5NH3^+
A) 1.5 * 10^-10 B) 1.2 * 10^-10 C) 1.8 * 10^11
Calculate the concentration of Her in a solution at 25 degrees C that has a pOH of (a) 9.19 (b) 12.18 (c) 10.96
A) 1.5 * 10^-5 M B) 1.5 * 10^-2 M C) 9.1 * 10^-4 M
Polyprotic acids. Consider ascorbic acid, H2C6H6O6. Ka1=8.1 * 10^-5, Ka2=1.6 * 10^-12 A) Write the dissociation equations for ascorbic acid B) What is the pH of 0.10 M solution of ascorbic acid? C) What is the concentration of absorb ion, C6H6O6^2-?
A) 1.6 * 10^-12 B) 2.55 C) 1.6 * 10^-6
An aqueous solution of a strong base has a pOH of 1.76 at 25 degrees C. Calculate concentration of base in the solution (a) if the base is NaOH (b) if the base is Ba(OH)2
A) 1.7 * 10^-2 M B) 8.7 * 10^-3 M
Calculate the hydronium ion concentration in a solution at 25 degrees C which the pH is (a) 4.76 (b) 11.95 and (c) 8.01
A) 1.7 * 10^-5 M B) 1.1 * 10^-12 M C) 9.8 * 10^-9 M
Calculate the pOH of the following aqueous solutions at 25 degrees C (a) 0.013 M LiOH (b) 0.013 M Ba(OH)2 (c) 9.2 * 10^-5 M KOH
A) 1.89 B) 1.59 C) 4.04
Determine the pH and percent ionization for acetic acid solutions at 25 degrees with concentration (a) 0.15 M (b) 0.015 M and (c) 0.0015 M
A) 11% B) 3.5% C) 11%
Determine the pOH of a solution at 25 degrees C in which the hydroxide ion concentration is (a) 5.7 * 10^-12 M (b) 7.3 * 10^-3 M and (c) 8.5 * 10^-6
A) 11.24 B) 2.13 C) 5.07
Complete the following table in which lists information about the measured acid dissociation constant of 3 unknown weak acid A) Ka=1.97 * 10^-12 B) pKa=8.60 C) Ka=3. * 10^-9 Find the Ka or pKa then order them by relative strength
A) 11.706, weakest acid B) 2.5 * 10^-9 second strongest C) 8.5 strongest acid
Calculate the pOH of an aqueous solution at 25 degrees C that is (a) 0011 M in HNO4 (b) 3.5 * 10^-3 M in Her and (c) 9.3 * 10^-6 M in HCl
A) 12.04 B) 11.54 C) 8.97
A reaction has a rate constant of 00117 s^-1 at 400.0 K and 0.689 s^-1 at 450.0 K. A) determine activation energy for the reaction in kJ/mol B) What is the value of the rate constant at 425 K
A) 122 kJ/mol B) 0.101 s^-1
The reaction 2A----> B is second order in A with a rate constant of 32.0 M^-1 * s^-1 at 25 degrees C. A) If [A]0=0.0075 M how long will it take for the concentration of A to drop to 0.0018 M Calculate half life for [A] 0=0.0075 M and for 0.0025 M
A) 13.2 s B) 4.17 s and 12.5 s
Iron is reduced to pure iron by smelting during which the iron (III) oxide in the ore reacts with carbon monoxide gas, like this: Fe2O3 (s) + 3CO2 (g) ----> 2Fe(s) + 3CO2 (g) Suppose an engineer decides to study the rate of this reaction. She prepares the four reaction vessels with 146.5 g of solid iron (III) oxide and 30.7 g of carbon monoxide gas each. Arrange each vessel by decreasing order of initial rate of reaction. One is the highest four is the lowest A: 5.0 L 1000 degrees C B: 5.0 L 1200 degrees C C) 5.0 L 1100 degrees C D) 5.0 L 1300 degrees C,
A) 4 B) 2 C) 3 D) 1
What are the pH, pOH, and [OH^-] of a 0.023 M solution of HClO4 B) An aqueous solution of HNO3 has a pH of 2.78. What is the concentration of the acid?
A) 4.4 * 10^-13 M B) 1.7 * 10^-3 M
Determine the pOH of a solution at 25 degrees C in which the hydroxide ion concentration is (a) 3.7 * 10^-5 M (b) 4.1 * 10^-7 M (c) 8.3 * 10^-2 M
A) 4.43 B) 6.39 C) 1.00
Calculate pH in titration of 50.0 mL of 0.120 M acetic acid by 0.240 M sodium hydroxide after the addition of (a) 10.0 mL of base (b) 25.0 mL of base and (c) 35.0 mL of base
A) 4.56 B) 8.83 C) 12.447
A buffer is prepared with 0.50 M CH3COOH and 0.50 M CH3COONa. A) Calculate the initial pH of buffer B) What is the pH after adding 0.020 mol of NaOH (s) to 1.0 L of the buffer solution in part a. C) what is the pH after adding 0.020 mol of HCl to 1.0 L of the buffer solution in part a
A) 4.74 B) 4.77 C) 4.71
A) What is the pH of a solution that is 0.010 M in HClO? Ka=3.0 * 10^-8 B) What is the pH of a solution that is 0.010 M in HClO and 2.0 * 10^-4 M in NaClO?
A) 4.76 B) 5.82
Determine the pH and percent ionization for hydrocyanic acid solutions if concentration (a) 0.25 M (b) 0.0075 M (c) 8.3 * 10^-5 M
A) 4.96 0.0044% B) 5.72, 0.026% C) 6.70, 0.24%
Identify the missing species X in each of the following nuclear equations: A) 212/84 Po ---> 208/82 Pb + X B) 90/38 Sr ---> X + 0/-1 B C) X ---> 0/+1B
A) 4/2 a B) 90/39 Y C) 18/9 F
Calculate the hydronium concentrations in a solution at 25 degrees C in which pOH is (a) 2.74 (b) 10.31 (c) 12.40
A) 5.5 * 10^-12 B) 2.0 * 10^-4 M C) 2.5 * 10^-2
Determine (a) Kb of the acetate ion (CH3COO^-) (b) Ka of the methyl ammonium ion (CH3NH3^+), (c) Kb of the fluoride ion (F^-) and (d) Ka of the ammonium ion (NH4^+)
A) 5.6 * 10^-10 B) 2.3 * 10^-11 C) 1.4 * 10^-11 D) 5.6 * 10^-10
Determine the pH of a solution at 25 degrees C in which the hydroxide ion concentration is (a) 2.8 * 10^-8 M (b) 9.9 * 10^-9 M and (c) 1.0 * 10^-11 M
A) 6.45 B) 6.00 C) 3.00
Calculate the pH of the following aqueous solutions at 25 degrees C (a) 9.5 * 10^-8 M NaOH (b) 6.1 * 10^-2 M LiOH (c) 6.1 * 10^-2 M Ba(OH)2
A) 6.98 B) 12.79 C) 13.09
Calculate the hydroxide concentration in a solution at 25 degrees C in which pH is (a) 11.89 (b) 2.41 (c) 7.13
A) 7.8 * 10^-3 M B) 2.6 * 10^-12 M C) 1.3 * 10^-7 M
The following reactions have the indicated equilibrium constant at 100 degrees C 1) 2NOBr (g) -------><------2NO (g) + Br2(g) Kc=0.014 2) Br2 (g) + Cl2 (g) ------><-----2BrCl (g) Kc=7.2 Determine the value of Kc for the following reactions at 100 degrees C A) 2NO (g) + Br2 (g) -----><------2NOBr (g) B) 4NOBr (g) -------><------- 4NO (g) + 2Br2 (g) C) NOBr (g) ------><------ NO (g) + 1/2 Br2 (g) D) 2NOBr (g) + Cl2 (g) -----><------ 2 NO (g) + 2BrCl (g) E) NO (g) + BrCl (g) -------><------- NOBr (g) + 1/2 Cl2 (g)
A) 71 B) 2.0 * 10^-4 C) 0.12 D) 0.10 E) 3.2
Determine the pH of a solution at 25 degrees C in which the hydronium concentration is (a) 3.2 * 10^-9 M (b) 4.0 * 10^-8 M (c) 5.6 * 10^-2
A) 8.49 B) 7.40 C) 1.25
Calculate the concentration of HNO4 in a solution at 25 degrees C that has a pH (a) 2.06 (b) 1.77 and (c) 6.01
A) 8.7 * 10^-3 M B) 1.7 * 10^-2 M C) 9.8 * 10^-7 M
use the table of data collected to answer the questions below T(K). k(s^-1) 300 3.9*10^-2 310. 1.1*10^-2 320. 2.8*10^-2 A) What is the activation energy for the reaction? B) What is the rate constant at 80 degrees C?
A) 80 kJ/mol B) 4.8 s^-1
Given that the value of Z is 26 and the value of A is 83 A) What is the nuclide? B) What is the amount of protons? C) What is the amount of neutrons?
A) 83/36 Kr B) 36 C) 47
Calculate hydroxide ion concentration in a solution at about 25 degrees in which the pOH is (a) 13.02 (b) 5.14 (c) 6.98
A) 9.5 * 10^-14 M B) 7.2 * 10^-6 M C) 1.0 * 10^-7 M
An aqueous solution of a strong base has a pH of 8.98 at 25 degrees C. Calculate the concentration of base in the solution (a) if the base is LiOH and (b) is the base is Ba(OH)2
A) 9.6 * 10^-6 M b) 4.8 * 10^-6 M
The preparations of two aqueous solutions are described in the table below. for each solution, write the chemical formulas of the major species present at equilibrium. You can leave out water itself. Write the chemical formulas for the species that act like acids, bases or neither in their respective columns. A) 2.1 mol of HNO3 is added to 1.0 L of a 1.3 M NH3 solution B) 0.1 mol of kOH is added to 1.0 L of a solution that is 0.6 M in both NH3 and NH4Br
A) Acids: HNO3, NH4^+ Bases: N/A Other: NO3- B) Acids: NH4^+ Bases: NH3 Other: K^+, Br^-
The preparations of two aqueous solutions are described in the table below. For each, write the chemical formulas of the major species present at equilibrium. You can leave our water itself. Write the chemical formulas of the species that act as acids, bases or neither in their respective columns A) 1 mol Her is added to 1.0 L of a 0.8 M NH3 solution B) 0.30 mol of HNO3 is added to 1.0 L of a solution that is 1.2 M in both NH3 and NH4Br
A) Acids: Her, NH4^+ Bases: N/A Other: Br^- B) Acids: NH4^+ Bases: NH3 Other: NO3-, Br^-
Identify the Lewis acid and Lewis base in the each of the following reactions A) C2H5OC2H5 + AlCl3 ----> (C2H5)2 OAlCl3 B) Hg^2+ (aq) + 4 CN^- (aq) -----> Hg (CN)4^2- (aq)
A) AlCl3 is a Lewis Acid and C2H5OC2H5 is the Lewis Base B) Hg^2+ is the Lewis acid and CN^- is the Lewis base
Predict what will happen in the experiments below A) A student sees tiny bubbles clinging to the inside of an unopened bottle filled with soda. He opens it and hears a loud hiss as gas escapes B) Two 250 mL samples of water are draw from a deep well bored into a large underground salt deposit. Sample 1 is from the top and is 42 degrees C. Sample 2 is from a depth of 150 m and is 8 degrees. both samples are allowed to come to 20 degrees C and 1 atm. NaCl precipitate is seen to from in sample 1
A) Bubbles will grow larger and some more may appear B) No precipitate will form in sample 2
Identify the Bronsted-Lowry acid, Bronsted-Lowry base and the conjugates of each A) C5H5N (aq) + H2O (l) ---> C5H5NH^+ (aq) + OH^- (aq) B) HNO3 (aq) + H2O (l) ----> NO3^- (aq) + H3O^+ (aq)
A) C5H5N= base H2O= acid C5H5NH^+=conjugate acid OH^-=conjugate base B) HNO3=acid H2O= base NO3^-= conjugate base H3O^+=conjugate acid
Write an equation and list the types of intermolecular forces that are involved A) CaCl2 (s) -> <- B) CH3OH (l) -><-
A) CaCl2 (s) -><- Ca^2+ (aq) + 2Cl^- (aq) ionic, dispersion and dipole-dipole B) CH3OH (l) -><- CH3OH (aq) dispersion, dipole-dipole, hydrogen bonding
Assign oxidation numbers to determine if each is a redox reaction of not. Identify the species oxidized and reduced A) CH4 (g) + 2O2 (g) ---> CO2 (g) + 2H2O (l) B) HCl (aq) + NH3 (aq) ---> NH4Cl (aq) C) PbS (s) + 4H2O2 (aq) ---> PbSO4 (aq) + 4H2O (l)
A) Carbon is oxidized and oxygen is reduced B) Not a redox reaction C) Sulfur is oxidized and oxygen is reduced
H2CO3 A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) Carbonic Acid B) Weak Acid C) H2CO3 (aq) + H2O (l) HCO3- (aq) + H3O + (aq) HCO3- (aq) + H2O (l) CO32- + H3O + (aq) D) Ka1=4.2* 10^-7 Ka2=4.8 * 10^-11 E) pH=3.56
Suppose the galvanize cell sketched below is powered by the following reaction: Fe (s) + CuCl2 (aq) ---> FeCl2 (aq) + Cu(s) A) Write a balanced equation for what happen at the cathode B) Write a balanced equation for what happens at the anode C) Of what substance is the rod in the anode made of? D) Of what substance is the rod in the cathode made of? E) what are the chemical species in the anode? F) What are the chemical species in the cathode?
A) Cu^2+ (aq) + 2e- --> Cu (s) B) Fe(s) ---> Fe^2+ (aq) + 2e- C) Fe D) Cu E) Fe^2+, Cl^- F) Cu^2+, Cl^-
For each system listed in the first column of the table below, decide (if possible) whether the change described in the second column will increase entropy S of the system, decrease S or leave S unchanged. If there is not enough information, say it A) A few moles of He gas is cooled from 51.0 degrees C to -10.0 degrees C while the volume is held constant at 15.0 L B) A few grams of liquid NH3 is cooled from 37.0 degrees C to -3.0 degrees C C) A few moles of CO2 gas is heated from -3.0 degrees C to 83.0 degrees C and also expands from a volume of 5.0 L to a volume of 12.0 L D) A few grams of liquid (CH3)2CO evaporates at a constant temperature of 80.0 degrees C
A) Delta S < 0 B) Delta S < 0 C) Delta S > 0 D) Delta S > 0
For each chemical reaction listed in the first column of the table below, predict the sign of the reaction entropy delta S. If it's not possible to decide with the information given, check not enough information A) H2SO4 (l) + H2O (l) ----> H3O^+ (aq) + HSO4^- (aq) B) BaCl2 (aq) + K2SO4 (aq) ----> BaSO4 (s) + 2KCl (aq) C) HCl (g) + NH3 (g) ---> NH4Cl (s)
A) Delta S > 0 B) Delta S < 0 C) Delta S < 0
For each system listed in the first column of the table below, decide if possible whether the change described in the second column increases the entropy S of the system, decreases it or leaves it unchanged. If you don't have enough information, say it A) 2.0 L of pure H2 gas and 20.0 L of pure Ar gas both at 5 atm and 28 degrees C are mixed with the pressure kept constant at 5 atm B) A liter of seawater at 15 degrees C is passed through a reverse osmosis filter, which separates into 750 mL of pure water and 250 mL of brine (very salty water) C) 10 g of KI and 2.0 L of pure water at 85 degrees C. The KI is dissolved in the water D) 300 mL of a solution made from KI dissolved in water. 0.5 g of KI crystalizes out of the solution without changing temperature E) A 0.35 M solution of sucrose in water and a beaker of pure water, both at 37 degrees C. The solution is put into a semipermeable bag immersed in the water and 50 mL of pure water flows through the bag into the sucrose solution
A) Delta S > 0 B) Delta S < 0 C) Delta S > 0 D) Delta S < 0 E) Delta S > 0
Here is a graph of the pressure of N2O5 in a reaction vessel during a certain chemical reaction. Use it to answer the questions below Start of line is at 24.971 atm Pressure at 100 seconds: 10.051 atm Tangent of line is at 19.198 atm and 210 s A) Is N2O5 being created or destroyed B) If N2O5 is being created or destroyed what is the rate at which it is being created or destroyed 100 seconds after the reaction begins. Round to 2 sig figs C) If N2O5 is being created or destroyed what is the average rate at which it is being created or destroyed during the first 100 seconds of the reaction. Round to 2 sig figs.
A) Destroyed B) 0.091 atm/s C) 0.15 atm/sec
Decide what intermolecular forces act between the molecules of each compound A) nitrogen trichloride B) hydrogen fluoride C) NOCl D) I2
A) Dispersion, dipole-dipole B) dispersion, dipole-dipole, hydrogen bonding C) dispersion, dipole-dipole D) dispersion
a galvanic cell is powered by the following redox reaction: 4Fe^2+ (aq) + N2H4 (aq) + 4OH- (aq) --->4Fe^2+ (aq) + N2 (g) + 4H2O (l) A) Write a balanced equation for the half reaction that takes place at the cathode B) Write a balanced equation for the half reaction that takes place at the anode C) Calculate cell voltage under standard conditions. Round to 2 decimal places
A) Fe^3+ (aq) + e- ---> Fe^2+ (aq) B) N2H4 (aq) + 4OH- (aq) ---> N2 (g) + 4H2O (l) + 4e- C) 1.93 V
Acetic acid and water react to form hydronium cation and acetic anion like this: CH3COOH (aq) + H2O (l) ----> H3O^+ (aq) + CH3CO2^- (aq) Imagine 219 mmol of CH3CO2- are removed from a flask containing HCH3CO2, H2O, H3O^+ and CH3CO2- at equilibrium A) What is the rate of the reverse reaction before any CH3CO2- has been removed? B) What is the rate of the reverse reaction just after CH3CO2- has been removed? C) What is the rate of the reverse reaction when the system has again reached equilibrium? D) How much less CH3CO2- is in the flask when the system again reached equilibrium?
A) Greater than zero, and equal to rate of the forward reaction B) Greater than zero, but less than the rate of the forward reaction C) Greater than zero, and equal, to the rate of the forward reaction D) some, but less than 219 mmol
Predict the relative strengths oxyacids in each of the following groups (a) HClO, HBrO and HIO (b) HNO3 and HNO2
A) HClO, HBrO and HIO B) HNO3 is stronger than HNO2
A certain half reaction has a standard reduction potential E=1.18 V. An engineer proposes using this half reaction at the cathode of a galvanic cell that must provide at least 0.90 V. The cell will operate under standard conditions. A) Is there a minimum standard reduction potential that the half reaction used at the cathode of this cell can have? If so, calculate it and round to 2 decimal places B) Is there a maximum standard reduction potential that the half reaction used at the cathode of this cell can have? If so, calculate it and round to 2 decimal places C) Write a balanced equation describing a half reaction that could be used at the cathode of this cell
A) NO B) Yes, 0.28 V C) H2SO3 (aq) + H2O (l) ---> HSO4- (aq) + 3H+ (aq) + 2e-
The reaction between NO2 and CO2 to produce NO and CO2 is thought to occur between two steps (1) NO2 + NO2 -----> NO + NO3 (2) NO3 + CO -----> NO2 + CO2 The experimental rate = k[NO2]^2 (a) Write the equation for the overall reaction (b) Identify the intermediates (c) Identify the rate-determining step
A) NO2 + CO ---> NO + CO2 B) NO3 C) step 1
What is (a) the conjugate base of HNO3^- (b) the conjugate acid of O^2- (c) the conjugate base of HSO4^3- and (d) the conjugate acid of HCO3^-
A) NO3^- B) OH^- C) SO4^2- D) H2CO3
Predict whether a 0.10 M solution of each of the following salts will be basic, acidic or neutral: (a) LiI (b) NH4NO3 (C) Sr(NO3)2 (D) KNO2 (e) NaCN
A) Neutral B) Acidic C) Neutral D) Basic E) Basic
A chemist is studying the following equilibrium, which has the given equilibrium constant at a certain temperature: N2 (g) + 3H2 (g) ----> 2NH3 (g) kp=3*10^2- 8.0 atm of N2 and 8.2 atm H2 A) Can you predict the equilibrium pressure of NH3 using only the tools available to you? B) If so, enter the equilibrium pressure of NO to 1 sig fig
A) No b) N/A
Determine whether each compound is soluble in hexane A) water B) propane C) ammonia D) hydrogen chloride
A) No, polar and hydrogen bonding B) Yes, nonpolar C) No, polar and hydrogen bonding D) No, polar
HClO4 A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) Perchloric Acid B) Strong acid C) HClO4 (aq) + H2O (l) H3O+ + ClO4- D) Ka=none E) -log (0.18)=0.74
Nitrogen and hydrogen react to form ammonia, like this: N2 (g) + 3H2 (g) ----> 2NH3 (g) Suppose a mix of N2, H2 and NH3 has come to equilibrium in a closed reaction vessel. Predict what change, if any, the perturbations in the table below will cause in the composition of the mixture in the vessel. Also decide whether the equilibrium shifts to the right or left: A) Some H2 is removed. The pressure of N2 and NH3 will do what? Where does the equilibrium shift? B) Some NH3 is added. The pressure of N2 and H2 will do what? Where does the equilibrium shift?
A) Pressure of N2 will rise and pressure of NH3 will drop. Equilibrium shifts left B) Pressure of both will rise and equilibrium will shift left
Write the reaction quotients for each of the following A) N2 (g) + 3H2 (g) ---><---- 2NH3 (g) B) H2 (g) + I2 (g) -----><------ 2HI (g) C) Ag^+ (aq) + 2NH3 (aq) -----><------ Ag (NH3)2^+ (aq) D) 2O3 (g) -----><----- 3O2 (g) E) Cd^2+ (aq) + 4Br^- (aq) -----><------ CdBr4^2- (aq) F) 2NO (g) + O2 (g) -----><----- 2NO2 (g)
A) Qc= [NH3]^2 / [N2] [H2]^3 B) Qc = [HI]^2 / [H2][I2] C) Qc= [Ag (NH3)2^+] / [Ag^+] [NH3]^2 D) Qc = [O2]^3 / [O3]^2 E) Qc = [CdBr4^2-] / [Cd^2+][Br^-]^4 F) Qc = [NO2]^2 / [NO]^2 [O2]
For the Haber reaction, N2 (g) + 3H2 (g) ----> 2NH3 (g) What happens when A) You add ammonia B) You remove nitrogen?
A) Reaction shifts left and more H2 and N2 are produced B) Reaction shift left, more H2 and N2 are produced
Precise measurements give the following masses: 1/1 H = 1.0078 u 4/2 He= 4.00260 u 1/0 n= 1.0086649 amu 0/-1 e=5.4858 * 10^-4 u 0/1 e 5.4858 * 10^-4 amu Now consider the following nuclear reaction 2 1/1 H + 2 1/0 n ---> 4/2 He A) Is energy released or absorbed? B) Calculate how much energy was released or absorbed. Give the answer in both kJ/mol and MeV
A) Released B) 2.73 * 10^9 kJ/mol and 28.3 MeV
Consider the reaction, 2NaHCO3 (s) -----> Na2CO3 (s) + H2O (g) + CO2 (g) delta H=128 kJ/mol What is the effect on the equilibrium position when the following changes occur A) CO2 is removed? B) Pressure of H2O is increased? C) Temperature is increased? D) Add NaHCO3? E) Add N2?
A) Shift right B) Shift left C) Shifts right and K will be larger D) No change, it is solid E) No change, it is not even in the reaction
Determine if each of the following is a spontaneous, non spontaneous or equilibrium process at the specified temperature A) H2 (g) + I (g) -----> 2HI (g) at 0 degrees C B) CaCO3 (s) ----> CaO (s) + CO2 (g) at 200 degrees C C) CaCO3 (s) ----> CaO (s) + CO2 (g) at 1,000 degrees C D) Na (s) ----> Na (l) at 98 degrees C
A) Spontaneous B) Unspontaneous C) spontaneous D) equilibrium
A student made some measurements on some electrochemical cells and calculated three quantities: The standard reaction free energy ΔG˚ The equilibrium constant k at 25.0 degrees C The cell potential under standard conditions Eo The results are listed below. Unfortunately, the student may have made some mistakes. Examine his results carefully and figure out if anything is wrong. Note: If there is a mistake, only one of the three will be wrong A) n=1 ΔG˚=-107 kJ/mol Eo=-1.11 V B) n=1 ΔG˚=95 kJ/mol Eo=-0.98 V C) n=1 ΔG˚=-37 kJ/mol Eo=-0.38 V
A) Standard Gibbs free energy is wrong B) k is wrong C) Standard cell potential is wrong
Sr(OH)2 A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) Strontium Hydroxide B) Strong Base C) Sr(OH)2 (aq) + H2O (l) Sr2+ (aq) + 2OH- (aq) D) None E) pH=13.56
A 25.0 mL sample of 0.25 M HNO3 is titrated with 0.15 M NaOH A) Identify the titrant and analyze. Which solution is in buret? B) Write a balanced chemical equation for neutralization reaction C) What is the general shape and features of this titration curve? D) What indicator would you select for this titration E) Calculate initial pH of the HNO3 F) At what volume does the equivalence point occur. Calculate the volume and pH G) Calulcate pH when 48.0 mL NaOH has been added
A) Titrant: NaOH Analyte: HNO3 B) HNO3 (aq) + NaOH (aq) ---> NaNO3 (aq) + H2O (l) C) picture D) Phenol red and bromcresol purple E) 0.60 F) 42 mL and 0.87 G) 12.11
Use the observations about each chemical reaction in the table below to decide the sign of the reaction enthalpy Delta H and reaction entropy Delta S A) This reaction is slower below 70 degrees C than above B) This reaction is spontaneous except about 140 degrees C C) This reaction is always spontaneous, but proceeds slower at temperatures below 2 degrees C D) This reaction is endothermic and proceeds slower at temperatures below 127 degrees C E) This reaction is spontaneous only below 70 degrees C F) The reverse of this reaction is always spontaneous, but proceeds slower at temperatures below 140 degrees C
A) Unknown and unknown B) Delta H is negative and delta S is negative C) Delta H is negative and delta S is positive D) Delta H is positive and delta S is unknown E) Delta H is negative and Delta S is negative F) Delta H is positive and delta S is negative
A chemist is studying the following equilibrium, which has the given equilibrium constant at a certain temperature: 2CH4 (g) ----> 3H2 (g) + C2H2 (g) kp=3*10^-10 He fills a reaction vessel at this temperature with 15 atm of methane gas. A) Can you predict the equilibrium pressure of NH3 using only the tools available to you? B) If so, enter the equilibrium pressure to 1 sig fig
A) Yes B) 0.02
A chemist is studying the following equilibrium, which has the given equilibrium constant at a certain temperature: N2 (g) + 2H2O (g) ----> 2H2 (g) + 2NO (g) kp=3*10^-8 He fills the reaction vessel with 8.0 atm of N2 and 7.5 atm of H2O A) Can you predict the equilibrium pressure of NO using only the tools available to you? B) If so, enter the equilibrium pressure of NO to 1 sig fig
A) Yes B) 0.02 atm
A certain half reaction has a standard reduction potential E=0.94 V. An engineer proposes using this half reaction at the anode of a galvanic cell that must provide at least 1.40 V. The cell will operate under standard conditions. A) Is there a minimum standard reduction potential that the half reaction used at the cathode of this cell can have? If so, calculate it and round to 2 decimal places B) Is there a maximum standard reduction potential that the half reaction used at the cathode of this cell can have? If so, calculate it and round to 2 decimal places C) Write a balanced equation describing a half reaction that could be used at the cathode of this cell
A) Yes, 2.34 V B) NO C) F2 (g) + 2e- ---> 2F- (aq)
Methane and water react to form carbon monoxide and hydrogen, like this: CH4 (g) + H2O (g) -----> CO (g) + 3H2 (g) Imaging 100 mmol CH4, 100 mmol H2O are added to an empty flask A) What is the rate of the forward reaction before any CH4 or H2O has been added? B) What is the rate of the forward reaction just after the CH4 and H3O have been added to the flask? C) What is the rate of the forward reaction at equilibrium? D) How much CH4 is in the flask at equilibrium
A) Zero B) Greater than zero, and greater than the rate of the reverse reaction C) Greater than zero, and equal to the rate of the reverse reaction D) Some, but less than 100 mmol
A galvanic celli s powered by by the following redox reaction: Zn^2+ (aq) + H2 (g) + 2OH- (aq) ---> Zn (s) + 2H2O (l) Answer the following questions about this cell A) Write a balanced equation for the half reaction that takes place at the cathode B) Write a balanced equation for the half reaction that takes place at the anode C) Calculate cell voltage under standard conditions. Round to 2 decimal places
A) Zn^2+ (a) + 2e- ---> Zn (s) B) H2 (g) + 2OH- (aq) ----> 2H2O (l) + 2e- C) 0.07 V
HC2H3O2 A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) acetic acid B) Weak Acid C) HC2H3O2 (aq) + H2O (l) C2H3O2- (aq) + H3O + (aq) D) Ka=1.8*10^-5 E) pH=2.74
Predict whether 0.10 M solution of each of the following salts will be basic, acidic or neutral (a) CH3COOLi (b) C5H5NHCl (c) KF (d) KNO3 (e) KClO4
A) basic B) acidic C) basic D) neutral E) neutral
Write the rate expressions for each of the following reactions: A) I^- (aq) + OCl^- (aq) ----> Cl^- (aq) + OI^- (aq) B) 2O3 (g) ---> 3O2 (g) C) 4NH3 (g) + 5O2 (g) -----> 4NO (g) + 6H2O (g)
A) delta [OI^-]/delta t B) 1/3 (delta [O2]/delta t) C) 1/6 (delta [H2O]/delta t
HF. A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) hydrofluoric acid B) weak acid C) HF(aq) + H2O(l) F-(aq) + H3O+(aq) D) Ka = 7.1 x 10-4 E) 1.94
Hydrogen sulfide (H2S) is a contaminant commonly found in natural gas. It is required by the reaction with O2 to produce elemental sulfur 2H2S (g) + O2 (g) ------><------2S(s) + 2H2O (g) For each of the following determine whether the equilibrium will shift to the the left, to the right or neither: (a) add some O2 (g) (b) remove some H2S(g), (c) remove some H2O (g) and (d) add some S(s)
A) left B) Right C) right D) no change
CH3NH2 A) Name B) Strong or weak acid/base C) ionization equation D) Ka or Kb value(s) look in book E) pH of a 0.18 M solution
A) methylamine B) Weak Base C) CH3NH2 (aq) + H2O (l) CH3NH3+ (aq) + OH- (aq) D) Kb= 4.4 * 10^-4 E) pH=11.95
Predict the sign of Delta S system for each process A) The boiling of water B) I2 (g) ---> I2 (s) C) CaCO3 (s) -----> CaO (s) + CO2 (g)
A) positive B) negative C) positive
Use the following information to solve the question below Experiment. [A] (M). [B](M). Initial Rate (M/s) 1. 0.12. 0.010 2.2*10^-3 2. 0.36. 0.010 6.6*10^-3 3. 0.12 0.020 2.2*10^-3 A) What is the rate law for the reaction? B) Calculate the rate constant C) What is the overall reaction order?
A) rate=k[A] B) 0.018 s^-1 C) First order
Some measurements of the initial rate of a certain reaction are given in the table below [H2]. [I2]. Initial rate of reaction 2.11 M 1.37 M. 0.239M/s 7.77 M. 1.37 M. 0.880 M/s 2.11 M. 0.194 M. 0.0338 M/s Use this information to write the rate law for this reaction and calculate the value of the rate constant k. Round value to 3 sig figs. A) rate=k B) k=
A) rate=k[H2][I2] B) k=0.0827 M^-1 * s^-1
Some measurements of the initial rate of a certain reaction are given in the table below [N2]. [H2]. Initial rate of reaction 2.35 M. 0.662 M. 9.00 * 10^ 5 M/s 2.35 M. 2.71 M. 1.51 * 10^7 M/s 8.31 M. 0.662 M. 3.18*10^6 M/s Use this information to write the rate law for this reaction and calculate the value of the rate constant k. Round value to 3 sig figs. A) rate=k B) k=
A) rate=k[N2][H2]^2 B) k=8.74*10^5 M^-2 * s^-1
Number of O atoms
Higher oxidation number of central atom means the stronger the acid. Or, the more oxygen atoms the stronger the acid
What are radicals?
Highly reactive, neutral species
What is the conjugate base of H2CO3?
HCO3-
Hydrochloric acid
HCl
What are the strong acids?
HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4
Chloric acid
HClO3
Perchloric acid
HClO4
What is the conjugate base of ClO4-?
HClO4
Enter the chemical formula of a binary molecular compound of hydrogen and a group 7A element that can be reasonable expected to be more acidic in aqueous solution than HBr
HI
Hydroiodic acid
HI
Which is the stronger acid? HI or H2Te?
HI
HNO3 or HNO2. Which is more acidic?
HNO3
Nitric acid
HNO3
Which of the following conjugate acid-base pairs will not function as a buffer? C2H5COOH and C2H5COO^-, HCO3- and CO3^2- and HNO3 and NO3-
HNO3 and NO3-
Nitric acid. What's the formula? Ionic or molecular? Strong or weak acid/base?
HNO3, molecular and strong acid
We have a conjugate base with the formula HONH2 and a Kb value of 1.1 * 10^-8. What is the formula and Ka value of the conjugate acid?
HONH3^+ 9.1 * 10^-7
Which is the stronger acid? HSO4^- or HSeO4^-
HSO4^-
What is the conjugate acid of S^2-?
HS^-
What is the conjugate base of H2S?
HS^-
HCl is a strong acid what are the species present when it dissolves in water?
H^+, Cl^-, H2O
H2CO3 is a weak acid what are the species present when it dissolves in water?
H^+, HCO3-, H2CO3, H2O
H2S is a weak acid what species are present when it dissolves in water?
H^+, HS^-,H2S, H2O
HIO3 is a strong acid what are the species present when it dissolves in water?
H^+, IO3^-, H2O
What is meant by volatile?
Having measurable vapor pressure
What is entropy?
How chaotic or disordered something's atoms or molecules are
What is entropy (S)?
How spread out or dispersed the system's energy is
What is the conjugate base of HI?
I^-
Nitrogen and hydrogen react to form ammonia, like this: N2 (g) + 3H2 (g) -----> 2NH3 (g) The reaction is exothermic. Suppose a mixture of N2, H2, and NH3, has come to equilibrium in a closed reaction vessel. Predict what change, if any, the perturbations in the table below will cause the composition of the mixture in the vessel. Also decide whether the equilibrium shifts to the right or left. Perturbation #1 The temperature is lowered. What will happen to the pressure of NH3? Which way will the equilibrium shift? Perturbation #2 The temperature is raised. What will happen to the pressure of N2? Which way will the equilibrium shift?
Perturbation #1: Pressure will go up and equilibrium shifts right Perturbation #2: The pressure will go up and equilibrium will shift left
Nitrogen and oxygen react to form nitrogen monoxide, like this: N2 (g) + O2 (g) -----> 2NO (g) The reaction is endothermic. Suppose a mixture of N2, O2, and NO has come to equilibrium in a closed reaction vessel. Predict what change, if any, the perturbations in the table below will cause in the composition of the mixture in the vessel. Also, deice whether equilibrium shifts to the right or left Perturbation #1 Temperature is raised. What will happen to the pressure of NO and which way will equilibrium shift? Perturbation #2 The temperature is lowered. What will happen to the pressure of O2 and which way will equilibrium shift?
Perturbation #1: The pressure will go up and equilibrium will shift right Perturbation #2: Pressure will go up and equilibrium will shift left
Hydrogen sulfide and oxygen react to form sulfur dioxide and water like this: 2H2S (g) + 3O2 (g) ----> 2SO2 (g) + 2H2O (g) Suppose a mixture of H2S, O2, SO2 and H2O has come to equilibrium in a closed reaction vessel. Predict what change, if any, will happen Perturbation #1 Some SO2 is added. What will happen to the pressure of H2S and O2. Which way will equilibrium shift? Perturbation #2 Some O2 is removed. What will have to the pressure of H2S and SO2. Which way will equilibrium shift?
Perturbation #1: the pressure of both will go up and the equilibrium will shift left Perturbation #2: The pressure of H2S will go up and the pressure of SO2 will go down. The equilibrium will shift left
Methane and hydrogen sulfide react to form carbon disulfide and oxygen, like this: CH4 (g) + 2H2S (g) ----> CS2 (g) + 4H2 (g) Suppose a mix of CH4, H2S, CS2 and H2 has come to equilibrium in a closed reaction vessel. Predict what change, if any, the perturbations in the table below will cause in the composition of the mixture in the vessel. Also, decide whether the equilibrium shifts to the right or the left Perturbation #1 Some H2 is added. What will it do to the pressure of CH4 and H2S? Which way will equilibrium shift? Perturbation #2 Some CH4 is removed. What will it do to the pressure of H2S and CS2? What way will the equilibrium shift?
Perturbation #1: the pressure of both will go up and the equilibrium will shift to the left Perturbation #2: The pressure of H2S will go up and the pressure of CS2 will go down. Equilibrium shifts left
What does a single vertical line mean?
Phase boundary
What is an electrode?
Piece of conducting metal in an electrochemical cell at which either oxidation or reduction takes place
What is a battery?
Portable, self-contained source of electric energy consisting of galvanic cells or a series of galvanic cells
KOH. What's the name? Ionic or molecular? Strong or weak acid/base?
Potassium hydroxide. Ionic
KNO3. What's the name? Is it ionic or molecular? Strong or weak acid/base?
Potassium nitrate, ionic
Q is greater than Ksp
Precipitation will continue until product of ion concentration is equal to Ksp
What is osmotic pressure (pi)?
Pressure required to stop osmosis
What are enzymes?
Proteins that speed up chemical reactions
A chemical engineer is studying the following reaction: CH4 (g) + 2H2S (g) -----> CS2 (g) + 4H2 (g) At the temperature the engineer picks, the equilibrium constant Kp for this reaction is 1.0 * 10^3. The engineer fills four reaction vessels with methane and hydrogen sulfide, and lets the reaction begin. he then measures the composition of the mixture inside each vessel from time to time. His first set of measurements are shown in the table below. Predict the changes in the compositions the engineer should expect next time he measures the compositions Reaction Vessel A CH4-5.56 atm H2S-2.72 atm CS2-4.53 atm H2-5.47 atm What are the expected changes in pressure for each? Reaction Vessel B CH4-5.07 atm H2S-1.73 atm CS2-5.02 atm H2-7.45 atm What are the expected changes in pressure for each? Reaction vessel C CH4-4.58 atm H2S-0.74 atm CS2-5.51 atm H2 9.43 atm What are the expected changes in pressure for each?
Reaction Vessel A: The pressure of the products will rise and the pressure of the reactants will drop Reaction Vessel B: No change Reaction C: The pressure of the product drops and the pressure of the reactants rise
What does it mean when ∆G=0?
Reaction is at equilibrium
What does it mean when ∆G is bigger than 0?
Reaction is not spontaneous in forward reaction
What does it mean when ∆G is smaller than 0?
Reaction is spontaneous in forward reaction
What happens when you add heat to the reactants side of: N2O4 (g) ---> 2NO2 (g)
Reaction shifts right and K is larger
What happens if you add heat to the products side of: N2 (g) + 3H2 (g) ----> 2NH3 (g)
Reactions shifts left and K is smaller
What does a positive standard reduction potential mean?
Redox reaction will favor the formation of products
What is the third law of thermodynamics?
S crystal at 0K=0
What is the entropy equation?
S=k ln W S=entropy k= Boltzmann constant (1.38 * 10^-23 J/K) W= number of possible arrangements
A 9.00 L tank at 0.5 degrees C is filled with 17.4 g of sulfur hexafluoride gas and 8.07 g of dinitrogen monoxide gas. You can assume both behave ideally under these conditions. Calculate mole fraction and partial pressure of each gas and the total pressure in the tank
SF6= 0.394, 0.29731 atm N2O=0.606, 0.45757 atm Total pressure=0.75488 atm
What is a standard hydrogen electrode?
SHL, a half cell based on the half reaction 2H+ (1 M) + 2e- ----> H2 (1 atm) which has a standard reduction potential of 0
HSO3^- is the conjugate acid of what species?
SO3^2-
What is the conjugate base of HSO4^-
SO4^2-
We have a conjugate acid with the formula HSO4^- and a Ka value of 0.012. What is the formula and Kb value of the conjugate base?
SO4^2- 8.3 * 10^-13
What does double vertical lines mean?
Salt bridge
What is a reaction quotient?
Same calculation for equilibrium constant except without equilibrium concentrations. Comparing Q with Keq tells us which direction the reaction will proceed in.
What phenomenon allows colloids to be distinguished from solutions?
Scattering of light
What are gels?
Semisolid systems consisting of dispersions of small or large molecules in an aqueous liquid vehicle rendered jelly-like through the addition of a gelling agent
Enter the chemical formula of a binary molecular compound of hydrogen and a group 4A element that can be reasonably expected to be less acidic in aqueous solution than GeH4
SiH4
When the solute and solvent are solid what is the state of the resulting solution?
Solid
When the solute is gas and the solvent is solid what is the state of the resulting solution?
Solid
What are sols?
Solid dispersed in a liquid or another solid
What are the three types of interactions in a solution?
Solute-solute interactions, solvent-solvent interactions and solute-solvent interactions
When there is more hydronium than hydroxide what does that mean?
Solution is acidic
When there is more hydroxide than hydronium what does that mean?
Solution is basic
If concentrations of a weak acid and a conjugate base differ by more than a factor of 10
Solutions does not have capacity to resist the change of pH
What moves through a semipermeable membrane in osmosis?
Solvent
What is the equation for the difference between the entropies of products and reactants
Standard Delta S of the reaction = sum of the absolute entropies of products - the sum of the absolute entropies of the products Note: Each species must be multiplied by its coefficient
What is standard E?
Standard reduction potential or the potential associated with a reduction half reaction at an electrode when the ion concentration is 1 M and gas pressure is 1 atm
A solution initially contains H2O. What is the initial type? If I were to add HNO3 what would the change in pH be?
Starts neutral, ends up having pH go down
What are carboxylic acids?
Strength depends on nature of R group
When comparing two acids with X in the same group
Strength goes up as you move down a group
What two factors influence extent of acid ionization?
Strength of H-X bond the stronger the bond the weaker the acid and polarity
What descriptors apply to H2SO4?
Strong acid, oxyacid and polyprotic acid
When comparing two acids with X in the same period
Stronger acids have a larger electronegativity of X
What does the term "like dissolves like" mean?
Substances that have similar types of intermolecular forces dissolve in each other
A translation state forms in a reaction when
Successful collision of reactants occurs
What is cell potential?
The difference in potential energy between the anode and the cathode in a voltaic cell
A substance dissolves as long as what?
The entropic encouragement is stronger than the endothermic discouragement
What is standard entropy?
The entropy of a substance at standard temperature and pressure, expressed per mole of substance
What is the standard free energy of formation?
The free energy change that occurs when 1 mol of a compound in its standard state is produced from its respective elements in their standard states under standard state conditions
What does it mean when Q=K?
The initial concentration are equilibrium concentrations. The system is already at equilibrium and there will be no net reaction in either direction
What is Kw?
The ionic product of water
What causes lower entropy?
Tightly-confined and immobile particles
What are aerosols?
Tiny solid and liquid particles suspended in the atmosphere
What does miscible mean?
Two liquids which can mix together
What is a conjugate pair?
Two species that differ by a proton (H+)
One way to distinguish a solution from a colloid is what?
Tyndall effect
What is electrolysis?
Use of electrical energy to drive a non-spontaneous redox reaction
Suppose a 250 mL flask is filled with 1.8 mol of CH4, 0.20 mol of H2S and 0.30 mol of CS2. This reaction becomes possible: CH4 (g) + 2H2S (g) -----><----- CS2 (g) + 4H2 (g) Complete the ICE table below. That is, list the initial molality for each compound, the change in molarity of each compound due to the reaction, and the equilibrium molarity of each compound after the reaction has come to equilibrium. Use x to stand for the unknown change in molarity of CS2. You can leave out the M symbol for molarity
[CH4]: 7.2-x [H2S]: 0.80-x [CS2]: 1.2 + x [H2]: 4x
Write the concentration equilibrium concentration constant expression for this reaction: Cu (s) + 2Ag^+ (aq) ----> Cu^2+ (aq) + 2Ag(s)
[Cu^2+] / [Ag^+]^2
Oxalic acid (H2C2O4) is a poisonous substance used mainly as a bleaching agent. Calculate concentration of all species present at equilibrium in a 0.10 M solution at 25 degrees C
[H2C2O4]=0.046 M [HC2O4^-]=0.054 M [H3O ^+]=0.054 M [C2O4^2-]=6.1 * 10^-5 M
0.500 mol of each reactant is mixed in 1.0 L container. After equilibrium is obtained, what are the concentrations of reactants and products? Kc=49.7 H2 (g) + I2 (g) ----> 2HI (g)
[H2] and [I2]=0.111 M [HI]=0.77814 M
Kc for the reaction of hydrogen and iodine to produce hydrogen iodine: H2 (g) + I2 (g) -----><------ 2HI (g) is 54.3 at 430 degrees C. Calculate equilibrium concentration concentration of all three species if the starting reactions are as follows: [H2]=0.00623 M, [I2]=0.00414 M, and [HI]=0.0424 M
[H2]=0.00676 M [I2]=0.00467 [HI]0.0414 M
Kc for the reaction of hydrogen and iodine to produce hydrogen iodine: H2 (g) + I2 (g) -----><------ 2HI (g) is 54.3 at 430 degrees C. What will the concentrations be at equilibrium if we start with 0.240 M concentrations of both H2 and I2?
[H2]=0.051 M [I2]=0.051 M [HI]=0.378 M
Fill in the left side of the equilibrium constant equation for the reaction of HClO with water
[H3O^+ ] [ClO^-] / [HClO] = Ka
What does Kw equal?
[H3O^+] [OH^-] = 1.0 * 10^-14
Write the concentration equilibrium constant expression for this reaction: CN^- (aq) + H2O (l) ----> HCN (aq) + OH^- (aq)
[HCN][OH^-] / [CN]
Write the equilibrium constant for this reaction H2SO4 (aq) -----> 2H^+ (aq) + SO4^2- (aq)
[H^+]^2- [SO4^2-] / [H2SO4]
Write the equilibrium constant for the reaction: H3PO4 (aq) ----> 3H^+ (aq) + PO4^3- (aq)
[H^+]^3 [PO4^3-] / [H3PO4]
Suppose a 500 mL flask is filled with 0.20 mol of H2 and 1.9 mol NH3. This reaction becomes possible: N2 (g) + 3H2 (g) -----><------ 2NH3 (g) Complete the table below so that it lists the initial molarity of each compound, the change in molarity of each compound due to the reaction, and the equilibrium molarity of each compound after the reaction has come to equilibrium. Use x to stand for the unknown change in molarity of N2.
[N2]=x [H2]=0.40 + 3x [NH3]=3.8-2x
A solution is prepared that is initially 0.12 M in NH3, a weak base, and 0.34 M in NH4Br complete the reaction table below. So that you can use it to calculate pH [NH3] [NH4^+] [OH^-]
[NH3] : 0.12, -x, 0.12-x [NH4^+]: 0.34, +x, 0.34+x [OH^-]: 0, +x, x
If initial concentrations of PCl5 is 1.00 mol/L, what is the equilibrium composition at 160 degrees C if Kc=0.0211 at this temperature? PCl5 ----> PCl3 + Cl2
[PCl5]=0.865 M [PCl3] and [Cl2]=0.135 M
What is a weak base?
a base that ionizes only partially in dilute aqueous solution to form the conjugate acid of the base and hydroxide ion
What is a homogenous catalyst?
a catalyst in the same phase as the reactants
What is an effective collision?
a collision that results in a reaction
What is a nuclear chain reaction?
a continuous series of nuclear fission reactions
What is a particle accelerator?
a machine that produces particles at near-light speeds for use in the study of the fundamental structure of matter
What is percent ionization?
a measure of the strength of an acid
What is percent ionization?
a measure of the strength of an acid %Dissociation=(H30+/HA)x100%
What is a positron?
a particle with the mass of an electron but a positive charge
What are foams?
gas in a matrix of liquid film.
If a solution with thymol blue indicator has pH=8.8, what color is visible?
green
HBr
hydrobromic acid
HCl
hydrochloric acid
HI
hydroiodic acid
Anion that is the conjugate base of a weak acid reacts with water to produce
hydroxide
Titration of a strong acid and strong base
initially- strong acid in the beaker; pH= -log(strong acid) before equivalence point- less strong acid; pH= -log (mol start - mol used)/total volume at equivalence point- ions and water in the beaker; pH=7 after equivalence point- strong base in the beaker; pOH=-log(mol added - mol start)/total volume
What is the Arrhenius equation?
k=Ae^(-Ea/RT)
What is the acid ionization constant?
ka
What does hypotonic mean?
less solute, more water
How do you calculate number of radioactive nuclei?
ln Nt/N0=-kt
What is the integrated first order rate law?
ln [A]t / [A]o = -kt
What is the units of Henry's Law constant?
mol/L*atm
What is molality (m)?
moles of solute/kg of solvent
What is molarity (M)?
moles of solute/liters of solution
What phenomenon is responsible for the changes in blood cells when administering intravenous solutions?
osmosis
What is the Henderson-Hasselbalch equation?
pH = pKa + log [base]/[acid]
HClO4
perchloric acid
As a result of spending time in a more oxygen poor environment, a human will
produce more hemoglobin
What are colligative properties?
properties that depend on the number of solute particles, but not on the type
What is a bronsted base?
proton (H+) acceptor
What is a bronsted acid?
proton (H+) donor
What are nucleons?
protons and neutrons
