Chem 1420 Final Exam

a sample of gas is found to contain only oxygen and carbon dioxide. The mole fraction of oxygen is 0.200. Express the oxygen concentration in units of percent by mass. a) 15.4 b) 8.33 c) 12.5 d) 22.2 e) 20.0

a) 15.4

which of the following pairs has the stronger acid listed first? a) H2SeO4, H2SeO3 b) HNO2 , HNO3 c) HBr, HI d) HClO2 , HClO3 e) HF, HCl

a) H2SeO4, H2SeO3

rank the standard molar entropy of the following from smallest to largest value: I. H2 O (l) II. H2O(g) III. H2 O2 (l) IV. H2 O2 (aq) a) I < III < IV < II b) I < III < II < IV c) II < IV < III < I d) IV < I < III < II e) III < I < IV < II

a) I < III < IV < II

which of the following substances will give an aqueous solution a ph<7? a) NH4Br b) Na2CO3 c) NaCH3COO d) CH3OH e) KI

a) NH4Br

A certain process has ∆Suni > 0 at 25°C. What does one know about the process? a) it is spontaneous at 25°C b) it will move rapidly toward equilibrium c) it is exothermic d) it is endothermic e) none of these choices is correct

a) it is spontaneous at 25°C

Hydrazine is used to eliminate dissolved, corrosive oxygen from the water used in high-pressure, high-temperature steam furnaces. In this reaction, the oxidation state of nitrogen changes from ___ to ___. a) +2, 0 b) -2, 0 c) -4, 0 d) +4, 0 e) -2, +1

b) -2, 0

Using the data below, calculate the standard free energy change (in kJ mol−1) for the following reaction at 25°C: CH4(g) + 2 O2(g) −−→ CO2(g) + 2 H2O(l) ∆G°f(CH4(g)) = -50.8 kJ/mol ∆G°f(CO2(g)) = -394.4 kJ/mol ∆G°f (H2O(l)) = -237.2 kJ/mol a) -580.8 b) -818.0 c) +818.0 d) 580.8 e) not enough information given

b) -818.0

which of the following aqueous solutions is most acidic? a) 0.10 M Be(NO3)2, Ka = 4 x 10^-6 b) 0.10 M Al(NO3)3, Ka = 1 x 10^-5 c) 0.10 M Ni(NO3)2, Ka = 1 x 10^-10 d) 0.10 M Pb(NO3)2, Ka = 3 x 10^-8 e) pure water

b) 0.10 M Al(NO3)3, Ka = 1 x 10^-5

Citric acid, Ka = 8.4 × 10^−4, would be most effective for preparation of a buffer with a pH of ______. a) 2 b) 3 c) 4 d) 5 e) 6

b) 3

consider the following reaction: COCl2(g) <-----> CO(g) + Cl2(g) A reaction mixture initially contains 1.6 M COCl2. Determine the equilibrium concentration of CO if Kc = 8.33 × 10^−4 a) 1.3 X 10^−3M b) 3.6 X 10^-2 M c) 1.5 X 10^-3 M d) 2.1 X 10^-2 M e) 4.2 X 10^-4 M

b) 3.6 X 10^-2 M

what is the [OH-} in a solution whose [H3O+] is 2.35 x 10^-3 M at 25°C? a) 2.35 x 10^-11 M b) 4.26 x 10^-12 M c) 4.26 x 10^-5 M d) 2.35 x 10^-17 M e) none of these

b) 4.26 x 10^-12 M

nuclides above the belt of stability can become more stable throwing which of the following processes? a) electron capture b) beta emission c) positron emission d) neutron bombardment e) gamma emission

b) beta emission

at 425°C, Kp = 55.2 for the following reaction: H2(g) + I2(g) <----> 2 HI(g) A cylinder at that temperature is found to contain 0.127 atm of H2, 0.124 atm of I2, and 1.055 atm of HI. Is the system at equilibrium? a) yes b) no, the reaction must shift toward reactants to establish equilibrium c) no, the reaction must shift toward products to establish equilibrium d) the volume of the container must be known before deciding e) the starting concentrations of all substances must be known before deciding

b) no, the reaction must shift toward reactants to establish equilibrium

the belt of stability describes the stable isotopes of atoms. As the atomic number increases, the neuron to proton ratio generally _______. a) decreases, because more protons than neutrons will increase stability. b) increases or decreases, depending on the element in question - there is no general trend c) increases since stability increases with increasing atomic mass. d) increases because when you get beyond Z = 20, you need an ever increasing number of neutrons vs. number of protons for the nucleus to be stable. e) remains 1:1. Every stable isotope of an atom has the same number of protons and neutrons.

d) increases because when you get beyond Z = 20, you need an ever increasing number of neutrons vs. number of protons for the nucleus to be stable.

what particle or type of radiation needs to be included to balance the reaction: 108 108 49In -----> 48Cd + ______

0 +1B

which reaction correctly depicts the mechanism of electron capture?

1 0 1 1H + -1e ----> 0n

select the nuclide that balances the following nuclear reaction: 147 4 62Sm ------> _______ + 2He

143 60Nd

Rank the following from highest to lowest boiling point: 1. Ne O || 2. CH3-C-CH3 3. CH3CH2CH3 4. CH3Ch2Ch2-OH 5. He

CH3Ch2Ch2-OH > O || CH3-C-CH3 > CH3CH2CH3 > Ne > He 4 > 2 > 3 > 1 >5

write Qc for the following reaction: 2 C6H6(g) + 15 O2(g) −↽−⇀− 12 CO2(g) + 6 H2O(g)

[CO2]^12 [H2O]^6 __________________________ [C6H6]^2 [O2]^15

Which is the solubility product expression for calcium phosphate, Ca3(PO4)2?

[Ca+2]^3[PO4-3]^2

write the Qc for the following reaction: Zn(s) + 2 Ag+(aq) <-----> Zn2+(aq) + 2 Ag(s)

[Zn+2] __________ [Ag+]^2

the voltaic cell made up of cobalt, copper, and their M+2 ions, has E°cell = +0.62 C. If E°red of the cathode half-cell is 0.34V, what is E°ox of the anode half-cell? Cu2+(aq) + Co(s) −−→ Cu(s) + Co2+(aq) a) +0.28 V b) +0.96 V c) −0.96 V d) −0.28 V e) None of these choices is correct.

a) +0.28 V

A 50.0-mL sample of 0.50 M HCl is titrated with 0.50 M NaOH. What is the pH of the solution after 28.0 mL of NaOH has been added to the acid? a) 0.85 b) 0.75 c) 3.8 d) 0.66 e) 0.49

a) 0.85

what is the boiling point of a solution containing 15.40 traps of urea (M = 60.06 g/mol), a non-volatile molecular solute, and 66.70 grams of water? the density of the solution is 1.120 g/mL. a) 102.0°C b) 1.8°C c) 98.0°C d) 107.0°C e) 101.8°C

a) 102.0°C

hydrogen peroxide decomposes into water and oxygen gas its a rate constant of 6.4 X 10^-5 s-1. What is the half life if the initial concentration of hydrogen peroxide is 1.7 M? a) 3.0 hours b) 1.5 hours c) 2.2 hours d) 3.7 hours e) 2.6 hours

a) 3.0 hours

what is the approximate pH range over which the indicator propyl red, Ka = 3.3 X 10^-6, would change its color? a) 4.5-6.5 b) 6.5-8.5 c) 3.5-5.5 d) 5.5-7.5 e) none of these choices is correcr

a) 4.5-6.5

Using the following data, calculate the boiling point of ethanol. ∆Hvap = 38.56 kJ/mol S° (C2H5OH 9l)) = 160.7 J/K/mol S°(C2H5OH(g)) = 270.4 J/K/mol a) 78.4°C b) 351.5°C c) 109.7°C d) -78.4°C e) 0.4°C

a) 78.4°C

which of the following is considered a lewis acid? a) BCl3 b) BF4 - c) CH3NH2 d) CH4 e) F-

a) BCl3

balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of H2C2O4 and H2O in the balanced reaction? MnO4−(aq) + H2C2O4(aq) −−→ Mn2+(aq) + CO2(g) a) H2C2O4 = 5, H2O = 8 b) H2C2O4 = 3, H2O = 2 c) H2C2O4 = 1, H2O = 4 d) H2C2O4 = 1, H2O = 1 e) H2C2O4 = 5, H2O = 1

a) H2C2O4 = 5, H2O = 8

which particle has the lowest penetrating power? a) alpha particle b) neuron particle c) gamma particle d) electron emission e) positron capture

a) alpha particle

the catalyzed pathways in a reaction mechanism has a _________ activation energy and thus causes a/an _______ reaction rate. a) lower, higher b) higher, higher c) higher, unchanged d) higher, lower e) lower, unchanged

a) lower, higher

which of the following statements concerning concentration units of solutions is true? a) molality is independent of temperature b) for percent by mass we need to know the molar mass of the solute c) for very dilute aqueous solutions the molarity is double the molality d) molarity is independent of temperature e) mole fraction is the preferred unit when measuring osmotic pressure

a) molality is independent of temperature

a solute is most likely to be highly soluble in a solvent if the solute is ________ and the solvent is ________. a) non-polar, carbon tetrachloride (CCl4) b) AgCl, water c) non-polar, polar d) hydrophobic, water e) an ionic compound, hexane (C6H14)

a) non-polar, carbon tetrachloride (CCL4)

the rate constant for a reaction is 1.234 M-1s-1. What is the overall order of the reaction? a) second b) zeroth c) first d) third e) cannot be determined from the given information

a) second

the substance HClO3 is considered a ____ a) strong acid b) weak acid c) strong base d) neutral compound e) weak base

a) strong acid

concerning galvanic cells, which statement is false? a) the anode is positively charged b) reduction occurs at the cathode c) cations from the salt bridge move toward the cathode d) only one statement is false e) electrons flow from the anode to the cathode

a) the anode is positively charged

at 298.15 K, when the partial press of methane (MCH4 = 16.04 g/mol) is 1.00 atm, the solubility of methane in water is 22.7 mg/L. What is Henry's law constant for methane in water at 298.15 K? a) 0.00126 mol/L/atm b) 0.00142 mol/L/atm c) 0.00227 mol/L/atm d) 1.42 mol/L/atm e) 0.0227 mol/L/atm

b) 0.00142 mol/L/atm

what is the pH of a solution that consists of 0.50 M H2C6H6O6 (ascorbic acid) and 0.75 M NaHC6H6O6 (sodium ascorbate)? Ka = 6.8 x 10^-5 a) 4.57 b) 4.34 c) 3.76 d) 3.99 e) 5.66

b) 4.34

Based upon the data provided, what is the rate constant for this reaction? NO2-(g) + O3(g) --> NO3-(g) + O2(g) a) 2.50 x 10^7 M-1 s-1 b) 5.00 x 10^5 M-1 s-1 c) 2.50 x 10^7 M-2 s-1 d) 1.00 x 10^4 s-1 e) 1.00 x 10^4 M-1 s-1

b) 5.00 X 10^5 M-1 s-1

which of the following substances has the greater solubility in water? a) CuBr, Ksp = 5.0 × 10^−9 b) NiCO3, Ksp = 1.3 × 10^−7 c) AgCN, Ksp = 2.2 × 10^-16 d) AgIO3, Ksp = 3.1 × 10^−8 e) MgCO3, Ksp = 3.5 × 10^−8

b) NiCO3, Ksp = 1.3 x 10^-7

which statement is true for an unsaturated solution? a) Q = Ksp b) Q < Ksp c) Q > Ksp d) Q doesn't not equal Ksp e) none of the above

b) Q < Ksp

a galvanic cell is prepared using sync and gold. its cell notation is: Zn(s) | Zn+2(aq, 1 M) || Au+3 (aq, 1M) | Au(s) which of the following processes occurs at the anode? a) Au+3 (aq) + 3e- ---> Au(s) b) Zn(s) ---> Zn+2 (aq) + 2e- c) Zn+2 (aq) + 2e- ---> Zn(s) d) Au(s) ---> Au+3 (aq) + 3e- e) 3Zn(s) + 2Au+3 (aq) ---> 3Zn+2 (aq) + 2 Au(s)

b) Zn(s) ---> Zn+2 (aq) + 2e-

for a reaction Qc = 75 while Kc = 195. Which of the following statements is accurate? a) The concentrations of the products will be about the same as the concentrations of the reactants when the system is at equilibrium. b) The reaction must proceed to the right to establish equilibrium. c) The reaction must proceed to the left to establish equilibrium. d) The concentrations of the products will be much smaller than the concentrations of the reactants when the system is at equilibrium. e) none of these is correct

b) the reaction must proceed to the right to establish equilibrium

which of the following aqueous solution would have the lowest freezing point? a. 0.10 m Na3PO4 b. 0.35 m NaCl c. 0.20 m MgCl2 d. 0.15 m C6H12O6 (glucose) e. 0.15 m CH3COOH (acetic acid)

b. 0.35 m NaCl

What is the freezing point of a 3.12 m solution of naphthalene in benzene? a) 16.0°C b) 4.89°C c) -10.5°C d) 21.5°C e) -16.0°C

c) -10.5°C

Consider the formation of ammonia: N2(g) + 3H2(g) --> 2NH3(g) If the rate of production of NH3 is 0.30 Ms-1, what is the rate of consumption of H2? a) 0.30 M s-1 b) 0.20 M s-1 c) 0.45 M s-1 d) 0.10 M s-1 e) 0.60 M s-1

c) 0.45 M s-1

Calculate the nuclear binding energy of 16-O given that nuclear mass of 16-O is 15.9906 amu. a) 2.04 X 10^-8 J b) 1.22 X 10^-9 J c) 2.04 X 10^-11 J d) 2.50 X 10^-9 J e) 2.50 X 10^-25 J

c) 2.04 X 10^-11 J

a 0.050 M solution of a weak base has [H3O+] = 3.77 X 10^-4 M. What is the Ka of this acid? a) 7.5 X 10^-3 M b) 7.0 X 10^-7 M c) 2.8 X 10^-6 M d) 2.6 X 10^-11 M e) 7.0 X 10^-8 M

c) 2.8 X 10^-6 M

the following first order reaction has a half life of 8.75 hours at 593K: SO2Cl2 --> SO2 + Cl2 How long will it take for the concentration of SO2Cl2 to fall to 12.5% of its initial value? a) 0.165 hr b) 2.33 hr c) 26.2 hr d) 8.75 hr e) 6.06 hr

c) 26.2 hours

Kw = 2.42 × 10^−14 at 37°C. What the is the pH of pure water at this temperature? a) 0.384 b) 13.616 c) 6.808 d) 7.192 e) 7.000

c) 6.808

Shown is a free energy diagram for the reaction N2O4(g) <---> 2 NO2(g) The free energy, G, is plotted, as a solid line, relative to the reactant species. For this reaction, Kp = 0.113. The initial conditions are indicated by the dotted line. Which one of the following statements is true: a) The initial conditions give QP < KP and ∆G < 0. b) Since ∆Srxn > 0, the products are favored at equilibrium. c) From the initial conditions, the reaction would proceed towards reactants to reach equilibrium, increasing the mole fraction of N2O4. d) The initial conditions correspond to the equilibrium composition. e) The equilibrium composition of reactants and products cannot be determined because the stoichiometry is not 1:1.

c) From the initial conditions, the reaction would proceed towards reactants to reach equilibrium, increasing the mole fraction of N2O4.

select the pair of substances in which an acid is listed followed by its conjugate base a) HPO4^-2,H2PO4- b) CH3COOH, CH3COOH2 + c) HCO3- , CO3^-2 d) H+, HCl e) NH3 , NH4 +

c) HCO3-, CO3^-2

consider the following process (treat all gases as ideal). I. The pressure of 1 mole of oxygen gas is doubled at constant temperature. II. Carbon dioxide expands to 10 times its original volume at constant temperature. III. The temperature of 1 mol of helium is increased 25◦C at constant pressure. IV. Nitrogen gas is compressed at constant temperature to half its original volume. V. A glass of water loses 100 J of energy in the form of heat. Which of these processes lead(s) to ∆Ssys > 0? a) I and II only b) I and IV only c) II and III only d) III and V only e) V only

c) II and III only

Which of the following statements is necessarily true? a) increasing activation energy and decreasing the temperature will increase the reaction rate b) increasing activation energy and increasing temperature will decrease the reaction rate c) increasing activation energy and decreasing temperature will decrease the reaction rate d) increasing activation energy and increasing temperature will increase the reaction rate e) only temperature has an effect on the rate of a reaction

c) increasing activation energy and decreasing temperature will decrease the reaction rate

When a weak acid is titrated with a strong base, the pH at the equivalence point a) is equal to 14.0 - pKb, where pKb is that of the base b) is less than 7.0 c) is greater than 7.0 d) is equal to 7.0 e) is equal to the pKb of the acid

c) is greater than 7.0

which of the following is an incorrect representation of the individual particle or nucleus? a) neutron: 1/0n b) gamma: 0/0Y c) positron: 0/-1B d) alpha particle: 4/2He e) proton: 1/1H

c) positron: 0/-1B

when a chemical system is at equilibrium, a) the concentrations of the reactants are equal to the concentrations of the products. b) the forward and reverse reactions have stopped. c) the concentrations of the reactants and products have reached constant values. d) Q has reached a maximum value. e) Q has reached a minimum value.

c) the concentrations of the reactants and products have reached constant values.

which of the following statements about the solubility of gases in liquids is FALSE? a) the solubility of a gas in a liquid is proportional to the pressure of the gas over the solution b) to quantity the solubility of a gas in a liquid we need Henry's Law constant c) the enthalpy of solution is usually positive (endothermic) d) the enthalpy of solution is usually negative (exothermic) e) the solubility decreases with increasing temperature

c) the enthalpy of solution is usually positive (endothermic)

A container was charged with hydrogen, nitrogen, and ammonia gases at 120◦C and the system was allowed to reach equilibrium. What will happen if the volume of the container is increased at constant temperature? 3 H2(g) + N2(g) <---> 2 NH3(g) a) there will be no effect b) the equilibrium will shift toward products c) the equilibrium will shift toward reactants d) the equilibrium constant will increase e) the equilibrium constant will decrease

c) the equilibrium will shift toward reactants

for the elementary reaction shown below, which one of the following statements may be assumed? 2A + B --> products a) the rate law is rate = k([A]^2 + [B]) b) the rate law is rate = k[2A][B] c) the rate law is rate = k[A]^2[B] d) the rate law is rate = k[A][B] e) the rate cannot be determined from the information

c) the rate law is rate = k[A]^2[B]

Which set of conditions, for the system, correspond to a process that is non-spontaneous at all temperatures? (A) ∆H < 0, ∆S > 0 (B) ∆H > 0, ∆S > 0 (C) ∆H > 0, ∆S < 0 (D) ∆H < 0, ∆S < 0 (E) all process can be made spontaneous by raising or lowering the temperature

c) ∆H > 0, ∆S < 0

The oxidation of hydrogen gas by oxygen gas forms the basis of the fuel cell, 2 H2(g) + O2(g) −−→ 2 H2O(l) This reaction has a ∆G° value of -474 kJ. What is the standard cell potential for this fuel cell? a) 4.91 V b) 0.005 V c) 1.54 V d) 1.23 V e) 2.46 V

d) 1.23 V

Fluorine-18 undergoes positron emission with a half-life of 1.10 X 10^2 minutes. If a patient is given a 248 mg dose for a PET scan, how long will it take for the amount of fluorine-18 to drop to 83 mg? (Assume that none of the fluorine is excreted from the body.) a) 1.32 X 10^2 minutes b) 2.11 X 10^2 minuted c) 3.00 X 10^2 minutes d) 1.74 X 10^2 minutes e) 99 minutes

d) 1.74 X 10^2 minutes

Determine E°cell for the galvanic cell described by the following reaction: 3 Zn(s) + 2 Au3+(aq) −−→ 3 Zn2+(aq) + 2 Au(s) a) 5.28 V b) 0.72 V c) 0.74 V d) 2.26 V e) 13.56 V

d) 2.26 V

A mixture of 0.600 M Br2 and 1.600 M I2 was made and allowed to come to equilibrium. Br2(g) + I2(g) <---> 2 IBr(g) Once the system reached equilibrium the concentration of IBr was 1.190 M. What is the value of Kc? a) 3.44 X 10^-3 b) 1.24 c) 1.47 d) 282 e) 325

d) 282

The Ksp of MgSO4 is 5.9 × 10^−3. What is the molar solubility of magnesium sulfate in 0.1 M MgCl2? a) 3.5 x 10^-5 M b) 7.7 x 10^-2 M c) 3.5 x 10^-6 M d) 4.2 x 10^-2 M based on x is small approximation e) 5.9 x 10^-2 M quadratic solution

d) 4.2 x 10^-2 M based on x is small approximation and e) 5.9 x 10^-2 M quadratic solution are both correct

the decomposition of N2O at 1000K has a rate constant of 0.76 s-1. If the initial concentration of N2O is 10.9 M,w what is the concentration of N2O after 9.6 seconds? a) 1.4 x 10^-3 M b) 1.0 x 10^-3 M c) 3.6 x 10^-3 M d) 7.4 x 10^-3 M e) 8.7 x 10^-3 M

d) 7.4 X 10^-3 M

Which of the following reactions would have the smallest value of K at 298 K? a) A + 2B −−→ C; E◦cell =0.98V b) A + B −−→ 3C; E◦cell =0.15V c) A + B −−→ C; E◦cell=1.22V d) A + B −−→ 2C; E◦cell =−0.030V e) More information is needed to determine.

d) A + B −−→ 2C; E◦cell =−0.030V

Consider a electrochemical cell based on the following redox reaction at 25◦C (1 atm): 2 Fe(s) + Cu2+(aq) −−→ 2 Fe2+(aq) + Cu(s) Which of the following statements is/are true at the point in time when this cell reaches equilibrium? I. Ecell = 0 II. Cu2+ = Fe2+ III. No work can be done by this cell. IV. E°cell=0 a) II, III, and IV only b) I, II, and III only c) II and IV only d) I and III only e) I only

d) I and III only

Consider the reaction: H2(g) + Br2(g) <-----> 2 HBr(g) what is the relation between Kc and Kp for this reaction? a) Kp = Kc/RT b) Kp = Kc/(RT)^2 c) Kp = (RT)Kc d) Kp = Kc e) Kp = (RT)^2Kc

d) Kp = Kc

Consider the following reaction mechanism: M+N -> Q+J Q+R -> D+Z Z+E -> N+B Identify the catalyst(s) in the above mechanism a) N, Q and Z b) M and B c) M only d) N only e) Q and Z

d) N only

an acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease? a) diluting the offer solution with water b) dissolving a small amount of solid sodium chloride c) adding a small amount of dilute sodium hydroxide d) adding a small amount of dilute hydrochloric acid e) dissolving a small amount of solid sodium acetate

d) adding a small amount of dilute hydrochloric acid

the rate of a reaction depends on ______. a) collision orientation b) collision frequency c) collision energy d) all of the above e) none of the above

d) all of the above

which statement below describes the graph representing the integrated rate law with an order of zero? a) plot of [A]t vs t having a straight line with a positive slope equal to k b) plot of 1/[A]t vs t having a straight line with a positive slope equal to k c) plot of 1/[A]t vs t having a straight line with a negative slope equal to −k d) plot of [A]t vs t having a straight line with a negative slope equal to −k e) plot of ln [A]t vs t having a straight line with a negative slope equal to −k

d) plot of [A]t vs. t having a straight line with a negative slope equal to -k

based on the following reaction coordinate diagram, which of the following statements is/are necessarily true? |. the reaction has two intermediates ||. the overall reaction is endothermic |||. its second step is slower than the first step. |V. there are two transition states a) | only b) | and || c) || and ||| d) ||| and |V e) |V only

d) ||| and |V

Iodine sublimes (solid converting directly to gas) at room temperature. Which of the following must therefore be true at this temperature? a) ∆Grxn = 0, ∆Hrxn > 0, ∆Srxn > 0 b) ∆Grxn < 0, ∆Hrxn > 0, ∆Srxn < 0 c) ∆Grxn = 0, ∆Hrxn > 0, ∆Srxn < 0 d) ∆Grxn < 0, ∆Hrxn > 0, ∆Srxn > 0 e) ∆Grxn < 0, ∆Hrxn < 0, ∆Srxn > 0

d) ∆Grxn < 0, ∆Hrxn > 0, ∆Srxn > 0

what is the sign of ∆Grxn for: H2O (s) ---> H2O(l) at 1 atm for the following temperatures: -1°C, 0°C, and 1°C, respectively? a) +, 0, and + b) +, +, and - c) -, -, and + d) -, 0, and + e) +, 0, and -

e) +, 0, and -

Kp = 4.00 X 10^-4 for the following reaction: 2 HCN(g) <----->H2(g) + C2N2(g) what is Kp for the following reaction: H2(g) + C2N2(g) <----> 2 HCN(g) a) 2.00 X 10^-4 b) 1.25 X 10^3 c) -4.00 X 10^-4 d) 4.00 X 10^4 e) 2.50 X 10^3

e) 2.50 X 10^3

what is the [H3O+] in a 0.10 M solution of formic acid, HCOOH? Ka = 1.8 x 10^-4 a) 1.8 x 10^-4 M b) 1.0 x 10^-1 M c) 8.4 x 10^-3 d) 1.8 x 10^-5 M e) 4.2 x 10^-3 M

e) 4.2 x 10^-3 M

For the reaction N2(g) + 3 H2(g) <---> 2 NH3(g) at 375°C, Kp = 8.1×10−6. Determine ∆G° (in kJ mol−1) at 375°C. a) 623.4 b) 36.6 c) 27.4 d) 15.9 e) 63.2

e) 63.2

calculate E°cell and indicate whether the overall reaction shown is spontaneous or non-spontaneous. I2(s) + 2e- <---> 2I-(aq); E° = +0.53 V CR+3 (aq) = 3E- <---> CR(S); E° = -0.74 V overall reaction: 2Cr(s) + 3I2(s) ---> 2Cr+3(aq) + 6I-(aq) a) E°cell = +1.27 V, non-spontaneous b) E°cell = -1.27 C, non-spontaneous c) E°cell = -1.27 V, spontaneous d) E°cell = +1.54 V, spontaneous e) E°cell = +1.27 V, spontaneous

e) E°cell = +1.27 V, spontaneous

which of the following statements is TRUE? a) Positrons are similar in ionizing power and penetrating power to beta particles. b) Beta decay occurs when a neutron changes into a proton while emitting an electron. c) An alpha particle is a helium 2+ ion. d) A positron is the antiparticle of the electron. e) All of the above are true.

e) all of the above are true

considering the chemical reaction below, what is the correct rate law? N2(g) + 3H2(g) --> 2NH3(g) a) The rate law is, rate = k [N2 ][H2]^2 b) The rate law is, rate = k [N2 ][H2]^3 c) The rate law is, rate = k [N2 ][H2]^1/2 d) The rate law is, rate = k [N2]2[H2]^3 e) The rate law cannot be determined from the given information.

e) the rate law cannot be determined from the given information