chemmy
The removal of copper from metallic ores has been a challenge since ancient times. Strong heating of copper(II) carbonate results in the formation of copper(II) oxide.Although the decomposition of copper(II) oxide into copper metal and oxygen gas is not thermodynamically favorable under standard conditions, it may be made favorable by adding carbon to the mixture. Do this question without a calculator.
-138
Calculate the DG° for the following equation: Do this without a calculator.
-142
a popular chemistry demonstration
-368
given the following data
-5756.6 kJ
What is the approximate density of the hydrogen gas produced at STP if 27.0 g of aluminum metal is added to 333 mL of 3.0 M hydrochloric acid? Solve without using a calculator.
.1
If 200ml of 0.60 M MgCl2
0.20 M Mg ion & 0.40 M Cl ion
A 57 gram block of metal at 92
0.60 J
The equilibrium constant for the reaction A- + H+ HA is called:
1/ka
If a sample of 27.0 g of aluminum metal is added to 333 mL of 3.0 M hydrochloric acid, the volume of hydrogen gas produced at standard temperature and pressure is: (Solve without using a calculator.)
11.2 L
A 5L vessel contains 2 moles of helium
12.0 atm
For weak acid, HX, Ka = 6.9 ´ 10-6. Calculate the pH of a 0.13 M solution of HX.
3.02
Consider this reaction at STP:
9L
Aqueous solution of barium chloride and silver nitrate
Ag+
Steel is an alloy of iron and other elements
C
The cyanate ion has three possible Lewis structures. Based on formal charges, which Lewis structure is the dominant structure; that is, the structure that best represents the cyanate ion?
C
What point on the graph represents pKa2?
C
Which choice has the bonds listed in order
C-O<C--O<CoO
The photoelectron emission spectrum for an unknown element is shown above. It's known that the element is NOT an alkali metal. The peak that corresponds to the valence electrons within the atom is
D
In which case must a reaction be spontaneous at all temperatures?
DH is negative, DS is positive.
A weak acid, HF, is in solution with dissolved sodium fluoride, NaF. If HCl is added, which ion will react with the extra hydrogen ions from the HCl to keep the pH from changing?
F
Which is the strongest base in this reaction?
F-
Which of the following reactions is associated with the definition of Kb?
F- + H2O HF + OH-
Which of the following statements is false?
F- is a weaker base than Br-
The conjugate acid and conjugate base of bicarbonate ion, HCO3-, are, respectively:
H2CO3 and CO32-
Which of the following has a non-zero standard enthalpy of formation?
H2O
Suppose a buffer solution is made from formic and (HCHO2) and sodium formate (NaCHO2). What is the net ionic equation for the reaction that occurs when a small amount of hydrochloric acid is added to the buffer?
H3O+(aq) + CHO2-(aq) ® HCHO2(aq) + H2O(l)
Consider the titration of 100.0 mL of the weak diprotic acid H2A (0.10 M) with 0.20 M NaOH. What are the major species at each of the following points in the titration? (Water is always assumed to be a major species.)
HA
consider 100ml
HCN, HC2H3O2, HF, HCl
all of the following are in aqueous solution which incorrect
HCN, cyanic acid and HBr
Which is the strongest acid of the following?
HClO2
Select the stronger acid from each pair:
HI HClO3 HClO3
The boiling points of hydrogen chloride and hydrogen bromide
HI and HF
The boiling points of hydrogen chloride and hydrogen bromide are given in the table below. Based on periodicity and intermolecular forces, which of the other two hydrogen halides would have a boiling point that is higher than that of HBr?
HI and HF
The following three equations represent equilibria that lie far to the right. HNO3(aq) + CN-(aq) HCN(aq) + NO3-(aq) HCN(aq) + OH-(aq) H2O(l) + CN-(aq) H2O(l) + CH3O-(aq) CH3OH(aq) + OH-(aq) Identify the strongest acid.
HNO3
In a chemical reaction that has first-order kinetics, which is true at constant temperature?
Half-life and k are both constant.
An industrial plant processes its waste water through a sedimentation tank that removes hazardous metals by precipitating them as insoluble carbonate salts. If sodium carbonate is gradually added to the tank, what would be the order of precipitation of the metals, Pb2+, Cu2+, Hg22+, and Zn2+ if each is » 1.0 ´ 10-4 M? ( Ksp PbCO3 = 7.4 ´ 10-14, Ksp CuCO3 = 1.4 ´ 10-10, Ksp Hg2CO3 = 8.9 ´ 10-17, and Ksp ZnCO3 = 1.4 ´ 10-11)
Hg22+, Pb2+, Zn2+, Cu2+
Which, if any of the following mixtures will result in a precipitate. You might need to know that the Ksp for AgCN is 2.2 ´ 10-16 and that for PbI2 is 7.9 ´ 10-9.I. a mixture that is 1.2 ´ 10-6 M AgNO3 and 2.4 ´ 10-10 M NaCNII. a mixture that is 2.3 ´ 10-4 M Pb(ClO4)2 and 4.6 ´ 10-3 M KI
I will II wont
Consider the reaction, which is exothermic as written, PCl5(g) D PCl3(g) + Cl2(g). Which of the following changes would result in the production of LESS Cl2(g)?I. adding PCl3(g)II. removing PCl3(g)III. reducing the volume of the containerIV. removing PCl5(g)V. increasing the temperatureVI. increasing the volume of the containerVII. adding PCl5(g)VIII. reducing the temperatureIX. adding a suitable catalyst
I, III, IV, V
The value of the equilibrium constant, K, is dependent on: I.the temperature of the systemII.the nature of the reactants and productsIII.the concentration of the reactantsIV.the concentration of the products
I,II
Which of the following are true at equilibrium for the reaction
I,II
Which of the following mixtures would result in a buffered solution?
Mixing 50.0 mL of 0.100 M HCl with 100.0 mL of 0.100 M NH3 (Kb = 1.8 ´ 10-5).
Which of the following substances contains both ionic and covalent bonds?
NaOH
For the process S8 (rhombic) ® S8 (monoclinic) at 110°C, DH = 3.21 kJ/mol and DS = 8.70 J/K × mol (at 110°C).Which of the following is correct?
This reaction is spontaneous at 110°C (S8 (monoclinic) is stable).
Which of the following statements concerning equilibrium is TRUE?
When two opposing processes proceed at the same rate, the system is at equilibrium.
Solve without using a calculator. The simplest formula for a compound made from element X (molar mass = 79.0 g/mol) that is 21.0% nitrogen by mass is
X2N3
In the reaction , all substances are gases. The recation is initiated by adding an equal number of moles of W and X. When equilibrium is reached,
X>W
A substance is found to be nonconductive, to have a relatively low melting point, and to be insolublein water. This is most likely
a molecular solid.
which of the following names is correct
all
n the reaction, NO3(g) + CO(g) → NO2(g) + CO2(g) the carbon in CO must collide with an oxygen in NO3 with sufficient energy to react. Which of the diagrams below would most likely result in the formation of products?
the 60 degree one
Non polar solutes dissolve more readily in nonpolar solvents than polar solvents because
the induced dipole of the solute molecule creates an induced dipole in the solvent molecule and London dispersion forces occur.
Consider the decomposition of potassium chlorate according to the reaction below. Which expression is needed to find the pressure of the O2 if 61.2 g of the potassium chlorate (molar mass = 122.4 g/ol) decomposes in a rigid 2.5-L container at a temperature of 525°C? (Assume all the chlorate decomposed to form the products). Do this without a calculator.
(.75)(.0821)(525+273)/2.5
Consider four 100g samples
(cp=0.14J)
What is the enthalpy change for the following reaction under standard conditions? Solve without a calculator.
-1076 kJ
Consider the gas phase reaction NO + O2 NO2 for which DH° = -56.91 kJ and K =1.46 ´ 106 at 25°C.Calculate DH° at 25°C for the following reaction: 2NO + O2 2NO2
-113.8 kJ
Consider the reaction shown below: Determine H
-550KJ
Determine DG° for the following reaction:CH4(g) + 2O2(g) ® CO2(g) + 2H2O(l) Substance DGf°(kJ/mol) CH4(g) -50.69 O2(g) 0 CO2(g) -394.4 H2O(l) -237.4
-818.8
how many moles of barium sulfide
.020
How many moles of sulfuric acid would completely react with 0.30 moles of potassium hydroxide in a titration? Solve without using a calculator.
.15
Do this without a calculator: The number of moles of Al(NO3)3 that must be added to water to form 2.00 L of 0.30 M NO31- ions is:
.20
An audio amplifier generates a great deal of heat than can be dissipated with heat-radiating metal fins. Which metal below (shown with its specific heat capacity) would be the best for this application?
.39
A student uses acetic acid to titrate a solution of copper(I) hydroxide to deteremine the concentration of the copper(I) hydroxide. If 30.0 mL of 0.250 M acetic acid is needed to neutralize 15.0 mL copper(I) hydroxide, what is the molarity of the copper(I) hydroxide? Do this without a calculator.
.5
Solve without using a calculator. Zinc sulfide reacts with oxygen to yield zinc oxide and sulfur dioxide as follows:
.67
You are given 5.00 mL of an H2SO4 solution of unknown concentration. You divide the 5.00-mL sample into five 1.00-mL samples and titrate each separately with 0.1000 M NaOH. In each titration the H2SO4 is completely neutralized. The average volume of NaOH solution used to reach the endpoint is 15.6 mL. What was the concentration of H2SO4 in the 5.00-mL sample?
.78
HA is a weak acid, which is 4.0% dissociated at 0.100 M. Determine the Ka for this acid. Do this without a calculator.
0.00016
Equal volumes of the following pairs of solutions are mixed. Which pair will produce a buffer solution?
0.10 mol L-1 HCl and 0.15 mol L-1 NH3
Consider the following indicators and their pH ranges: Methyl orange3.2-4.4Methyl red4.8-6.0Bromothymol blue6.0-7.6Phenolphthalein8.2-10.0Alizarin yellow10.1-12.0 Assume an indicator works best when the equivalence point of a titration comes in the middle of the indicator range. For which of the following titrations would methyl red be the best indicator?
0.100 M NH3 (Kb = 1.8 ´ 10-5) + 0.100 M HCl
what is the molarity of a solution containing ClO2
0.20M
Which of the following solutions would be described as a buffer solution?
0.25 M CH3COOH and 0.20 M NaOH
Which of the following mixtures would NOT be described as a buffer solution?
0.25 M HNO3 and 0.15 M KNO3
For the reaction given below, 2.00 moles of A and 3.00 moles of B are placed in a 6.00-L container.
0.325 mol/L
If 7 moles of sulfur
0.33 mol S
What is the molarity of a sodium hydroxide solution if 28.7 mL of this solution reacts exactly with 22.30 mL of 0.253 M sulfuric acid?
0.393 M
Calculate the pH of 0.203 M HNO3(aq).
0.693
Which of the following result(s) in an increase in the entropy of the system?
1 3 and 4
A reaction is first order with respect to [X] and second order with respect to [Y]. When [X] = 0.20 M and Y = 0.20 M the rate is 8.00 ´ 10-3 M min-1. The value of the rate constant, including correct units, is: (Do this without a calculator)
1.00 M-2 min-1
15.0 mL of 0.50 M NaOH is added to a 100.-mL sample of 0.457 M NH3 (Kb for NH3 = 1.8 ´ 10-5). What is the equilibrium concentration of NH4+ ions?
1.1 ´ 10-4 M
What volume of water must be added to 11.1 mL of a pH 2.0 solution of HNO3 in order to change the pH to 4.0?
1.10 ´ 103 mL
Determine the [OH1-] for 0.25 M methylamine, CH3NH2. Do this without a calculator.
1.10-2
How many moles of Ca(NO3)2 must be added to 1.0 L of a 0.182 M KF solution to begin precipitation of CaF2? For CaF2, Ksp = 4.0 ´ 10-11.
1.2x10-9
consider figures 1 and 2 below
1.33 atm
Consider Figures 1 and 2 below. On the right is a key to identify the gases in the problems.
1.33atm
For the reaction N2O4(g) 2NO2(g), Kp = 0.148 at a temperature of 298 K. What is Kp for the following reaction?10NO2(g) 5N2O4(g)
1.41 x 104
Sucrose, C12H22O11, has a molar mass of 342 g/mol. How many atoms of carbon are there in 684 g of sucrose. Do this without a calculator.
1.45 x 1025
a 20g sample of metal
1.5 J/°C
Calculate the pH of a 0.031 M strong acid solution.
1.51
A 100. mL sample of 0.10 M HCl is mixed with 50. mL of 0.11 M NH3. What is the resulting pH? (Kb for NH3 = 1.8 ´ 10-5)
1.52
A solution of hydrochloric acid of unknown concentration was titrated with 0.23 M NaOH. If a 100.-mL sample of the HCl solution required exactly 10. mL of the NaOH solution to reach the equivalence point, what was the pH of the HCl solution?
1.6
hydrogen gas, iodine vapor
1.6
In a closed rigid system, 7.0 mol CO2 , 7.0 mol Ar, 7.0 mol N2 , and 4.0 mol Ne are trapped, with a total pressure of 10.0 atm. What is the partial pressure exerted by the neon gas? Solve without using a calculator.
1.6 atm
If Ka for HCN is 6.17 ´ 10-10, what is Kb for CN-?
1.62 ´ 10-5
A 20.0 g sample of a hydrated compound is placed into a crucible and heated. The data table for this laboratory investigation is shown below.
1.7402 g
It is observed that 7.50 mmol of BaF2 will dissolve in 1.0 L of water. Use these data to calculate the value of Ksp for barium fluoride.
1.7x10-6
Calculate the pH of a 2.3 ´ 10-3 M KOH solution.
11.36
Calculate the pH of a 0.47 M NH3 (Kb = 1.8 ´ 10-5) solution.
11.46
The Ksp of a hypothetical metllic hydroxide, MOH, is 1.0 ´ 10-4. What is the pH of a saturated solution of MOH? Do this without a calculator
12
A 0.372-g sample of NaOH(s) is added to enough water to make 250.0 mL of solution. The pH of this solution is:
12.571
Calculate the pH of a 0.51 M solution of KOH.
13.71
Calculate the pOH of a 4.9 M solution of HCl.
14.69
For the reaction DH° = 126.4 kJ/mol and DS° = -74.9 J/K mol.At 361°C, what is DG° ?
173.9
which of the following most closely estimates
1g/L
What is the electron configuration for Zn2+?
1s22s22p63s23p63d10
If the concentration of the HF in this reaction is 0.1 M, what is an approximate pH of the solution? Do this without a calculator.
2
A solution with initial concentrations of 6.00 M Fe3+ and 10.0 M SCN1- is allowed to reach equilibrium. At equilibrium it is found that the concentration of FeSCN2+ is 4.00 M. What are the equilibrium concentrations of the Fe3+ and SCN1-? Do without a using a calculator.
2 & 6
If 103.5 g of XeF4 is reacted with excess water, how many moles of hydrofluoric acid are produced? Molar mass of XeF4 is 207 g/mol. Do this without a calculator.
2 mol
the noble gas xenon was not discovered
2 mol
Barium iodate has a Ksp of 4.0 ´ 10-9. What is the iodate ion concentration in a saturated solution of barium iodate? Do this without a calculator
2.0 ´ 10-3 M
Barium iodate has a Ksp of 4.0 ´ 10-9. What is the iodate ion concentration in a saturated solution of barium iodate? Do this without a calculator.
2.0 ´ 10-3 M
HA is a weak, monoprotic acid that dissociated according to the equation
2.0 ´ 10-5 M
The concentration of OH- in a saturated solution of Mg(OH)2 is 3.63 ´ 10-4 M. The Ksp of Mg(OH)2 is
2.4x10-11
Ammonia and oxygen react to establish the following equilibrium:
2.5 mol
Solve without using a calculator. Which of the following is a reasonable estimate for the volume of a balloon that has been filled with 300 g of oxygen gas at STP?
200L
which of the following is a reasonable estimate for the volume
200L
For which of the following processes would DS° be expected to be most positive?
2NH4NO3(s) ® 2N2(g) + O2(g) + 4H2O(g)
Consider the following processes: I.condensation of a gasIIincreasing the volume of 1.0 mol of an ideal gas at constant temperatureIII.dissolving sugar in waterIV.heating 1.0 mol of an ideal gas at constant volume For how many of these is DS positive?
3
how many of the following molecules have two pi
3
For two first-order reactions of different substances A and X
3 moles of A will react more rapidly than 3 moles of X.
The spectrum implies that the e-
3 shells and 4 subshells
Hydrogen gas at a pressure of 9.0 atm is added to a container containing 5.0 atm of iodine vapor. The resulting reaction is allowed to come to equilibrium, and it is found that the final pressure of iodine vapor is 2.0 atm. What is the Kp value for the following reaction? (Do without using a calculator).
3.0
What is the maximum concentration of iodide ions that will precipitate AgI but not PbI2 from a solution that is M each in Ag+ and Pb2+? For AgI, Ksp = 1.5 ´ 10-16 and for PbI2, Ksp = 1.4 ´ 10-8.
3.1x10-3
Calculate the pH of a solution that is 0.50 M in HF (Ka = 7.2 ´ 10-4) and 0.95 M in NaF.
3.42
Given that the Ka for HOCl is 3.45 ´ 10-8, calculate the K value for the reaction of HOCl with OH-.
3.45 ´ 106
Chromate ion is added to a saturated solution of Ag2CrO4 to reach 0.78 M CrO42-. Calculate the final concentration of silver ion at equilibrium (Ksp for Ag2CrO4 is 9.0 ´ 10-12).
3.4x10-6
Calculate the pH of the following aqueous solution: 0.66 M HOCl (pKa = 7.46)
3.82
Phosphorus can be produced by reacting calcium phosphate, silicon dioxide, and carbon at high temperatures according to the following equation:
35
The formation of an aluminum ion occurs when 3 electrons are removed. Which electron would require the most energy to remove?
3s bc higher attractive forces
A weak acid, HZ, has a Ka = 1.8 ´ 10-7. What is the pH of a 0.10 M solution of HZ? Do this without a calculator.
4
Ammonium hydrogen sulfide will decompose into ammonia gas and hydrogen sulfide gas when heated. Consider the equilibrium system
4.0 x 10-2
The salt MX2 has a solubility of 1.0 ´ 10-4 M. Determine the Ksp for MX2. Do this without a calculator.
4.0 ´ 10-12
The in a saturated solution of is 5.93 ´ 10-3 M. Calculate the Ksp for .
4.12x10-10
Determine the percent dissociation of a 0.18 M solution of hypochlorous acid, HClO. The Ka for the acid is 3.5 ´ 10-8.
4.4 ´ 10-2 %
what is the sodium ion concentration
4.5M
A 300.0-mL saturated solution of copper(II) peroidate, Cu(IO4)2, contains 0.30 grams of dissolved salt. Determine the Ksp.
4.5x10-3
What is the pH for a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka of CH3COOH = 1.8 ´ 10-5
4.63
The molar solubility of AgCl (Ksp = 1.6 ´ 10-10) in 0.0035 M sodium chloride at 25°C is:
4.6x10-8
You have a 250.-mL sample of 1.28 M acetic acid (Ka = 1.8 ´ 10-5). Calculate the pH of the best buffer.
4.74
a sample of 25ml of .120
40.0 mL
Use the following info to calculate the H-Cl bond
425 KJ
As O2(l) is cooled at 1 atm, it freezes at 54.5 K to form Solid type I. At a lower temperature, Solid type I rearranges to Solid type II, which has a different crystal structure. Thermal measurements show that DH for the type I ® type II phase transition is -743.07 J/mol, and DS for the same transition is -17.0 J/K mol. At what temperature are Solid types I and II in equilibrium?
43.7
Elemental sulfur exists in two crystalline forms, rhombic and monoclinic. From the following data, calculate the equilibrium temperature at which monoclinic sulfur and rhombic sulfur are in equilibrium. DHf° (kJ/mol) S° (J/K mol) S (rhombic)031.880S (monoclinic)0.3032.552
446
If K = 0.144 for A2 + 2B 2AB, then for 4AB 2A2 + 4B, K would equal:
48.2
Which of the following solutions will be the best buffer at a pH of 9.26? (Ka for HC2H3O2 is 1.8 ´ 10-5, Kb for NH3 is 1.8 ´ 10-5).
5.0 M NH3 and 5.0 M NH4Cl
What is the percent dissociation of HNO2 when 0.064 g of sodium nitrite is added to 120.0 mL of a 0.057 M HNO2 solution? Ka for HNO2 is 4.0 ´ 10-4.
5.2%
Consider the reaction At 1273 K, the Kp value is 167.5. What is the at equilibrium if the is 0.17 atm at this temperature?
5.3 atm
Calculate Kp for using the following data: Kp = 2.3 ´ 106 Kp = 1.8 ´ 1037
5.4 x 10-13
Initially 2.0 moles of N2(g) and 4.0 moles of H2(g) were added to a 1.0-liter container and the following reaction then occurred: 3H2(g) + N2(g) 2NH3(g)The equilibrium concentration of NH3(g) = 0.55 moles/liter at 700.°C. The value for K at 700.°C for the formation of ammonia is:
5.5 x 10-3
A solution contains 0.250 M HA (Ka = 1.0 ´ 10-6) and 0.45 M NaA. What is the pH after 0.17 mole of HCl is added to 1.00 L of this solution?
5.82
Which of the following mixtures would be classified as a buffer solution?
50 mL of 0.100 M CH3COOH and 25 mL of 0.100 M NaOH
Which of the following pairs of 0.100 mol L-1 solutions, when mixed, will produce a buffer solution?
50 mL of aqueous CH3COOH and 25 mL aqueous CH3COONa
when 16g of methane
50%
How much 12.0 M hydrochloric acid must be used to prepare 2.00 L of a 3.00 M hydrochloric acid solution? Do this without a calculator.
500ml
use the following data reactions to calculate the energy of an H-F
564 KJ
The solution containing the purple permanganate ion can be analyzed spectrophotometrically to determine the concentration of permangante. The colorimeter to be used has only four available wavelengths. Considering the color of permanaganate ion in solution, which wavelength should be chosen to get the maximum absorbance of light in the permanganate sample?
565
You have a 250.-mL sample of 1.250 M acetic acid (Ka = 1.8 ´ 10-5). Assuming no volume change, how much NaOH must be added to make the best buffer?
6.25
At 65°C, the ion-product constant of water, Kw, is 1.20 ´ 10-13. The pH of pure water at 65°C is:
6.46
What is the pOH of pure water at 65oC? (Kw at 65oC = 1.20 ´ 10-13)
6.460
Calculate the [H+] in a 0.068 M solution of HCN, Ka = 6.2 ´ 10-10.
6.5 ´ 10-6 M
Which of the following solutions contains the largest number of ions?
600ml
For a certain process at 355 K, DG = -11.8 kJ and DH = -9.2 kJ. Therefore, DS for the process is
7.3
A solution of 2.9 M weak acid is 0.52% ionized. What is the Ka value of this acid?
7.9 ´ 10-5
Solve without using a calculator. Substance AB2 is 60.0% A by mass. What is the percent A by mass for substance AB?
75.0%
A 10 lane olympic sized pool contains
8.4x 10 8 KJ
Determine the equilibrium constant for the system N2O4 2NO2 at 25°C. The concentrations are shown here: [N2O4] = 2.32 x 10-2 M, [NO2] = 1.41 x 10-2 M.
8.57 ´ 10-3
a 25ml sample of .10
8.72
The standard free energy of formation of KCl(s) is -408.8 kJ/mol. DG° for the reaction 2KCl(s) ® 2K(s) +Cl2(g) is:
817.6
Consider The reaction was initiated by adding 15.0 moles of NO to a 1.0-L flask. At equilibrium, 3.0 moles of oxygen are present in the 1.0-L flask. The value of K (do without a calculator) must be
9
Calculate the pH of the following aqueous solution: 0.52 M aniline (pKb = 9.42)
9.15
Calculate the pH of a 0.49 M solution of NaC2H3O2 (for HC2H3O2 Ka = 1.8 ´ 10-5).
9.22
The solubility of an unknown salt, M2Z, in a 0.0768 M CaZ solution is mol/L. Calculate the Ksp for M2Z.
9.6x10-20
The following question refers to a 2.0-liter buffered solution created from 0.72 M NH3 (Kb = 1.8 ´ 10-5) and 0.26 M NH4F. What is the pH of this solution?
9.70
Calculate the pH of a solution made by mixing 100.0 mL of 0.635 M NH3 with 100.0 mL of 0.100 M HCl. (Kb for NH3 = 1.8 ´ 10-5)
9.98
The Ksp of an unknown salt, MZ2, is . Calculate the solubility (in mol/L) of MZ2 in a 0.0230 M solution of CaZ2.
9x10-12
A 8.5 ´ 10-3 M solution of a weak acid is 4.6% dissociated at 25°C. In a 8.5 ´ 10-4 M solution, the percentage of dissociation would be
> 4.6%
Gas A2 reacts with B2 to form gas AB at constant temperature.
A
Which of the following statements is true concerning the relative solubility of silver chloride? All samples are at the same temperature.
AgCl is less soluble in 1.0 M AgNO3 than it is in pure water.
When placed in order of increasing atomic radius, what is the correct order for the elements, Al, Ca, and Mg?
Al, mg, ca
The salt BX, when dissolved in water, produces an acidic solution. Which of the following could be true?
All of the above could be true.
Which of the following statements is FALSE:
At equilibrium, the reaction has stopped
The exothermic reaction, 2 Cu(s) + O2(g) " 2 CuO(s), is spontaneous
At low temperatures
Equal volumes of equimolar H2S and OH1- are combined. Which diagram represents the resultant solution?
B
When propane burnse in air, heat is released.
B
aqueous solutions of Na2CO3 (table thing)
B
a .010mole sample of k2so4
BaSO4 would precipitate, but Ag2SO4 would not.
which of the following ionic compounds has the largest lattice
BeO
Which of the following is true?
By thermodynamically favored we mean that the reaction or process will always proceed to the right (as written) even if very slowly. Increasing the temperature may speed up the reaction, and it generally affects the spontaneity of the reaction.
which pairs of elements is likely to produce a highly covalent
C and F
which of the following molecules contains the shortest C-C
C2H2
The vapor pressure increases in a predictable order as shown as
C2H5 and ends with Ne
Each of the following salts has a solubility of 1.0 ´ 10-5 M. Rank the salts in order of lowest to highest Ksp.AX, B2X, C2X3, D3X
C2X3 < D3X < B2X < AX
Which of the following processes should show the greatest increase in entropy?
C6H6(l) + 15/2 O2(g) " 6 CO2(g) + 3 H2O(g)
Which of these compounds would you predict to have the highest boiling point?
CBr4
As indicated by the lewis structures, which of the following
CH3O
which ion listed has no resonance structures
CN-
The equilibrium constants (Ka) for HCN and HF in H2O at 25°C are 6.2 ´ 10-10 and 7.2 ´ 10-4, respectively. The relative order of base strengths is:
CN- > F- > H2O
Which solute would dissolve in carbon tetrachloride, CCl4?
CS2
Three ionic salts, AX, BX2, and CX3, each have a solubility of 2 ´ 10-5 M. Which of the following correctly ranks the Ksp of the three salts from least to greatest?
CX3 < BX2 < AX
Which of the following correctly ranks the following species from smallest to largest ionic radius?
Ca2+, K1+, Cl1-, S2-
Order the following in increasing rate of effusion
Cl2<NO2<F2
Given the following values of pKa, determine which is the weakest base of the answers listed. AcidpKaHClO21.95HClO7.54HCOOH3.74HF3.17HNO23.15
ClO2
Solve without using a calculator. Analysis of a sample of an oxide of chromium is reported as 26 g of chromium and 12 g of oxygen. From these data determine the empirical formula of this compound.
Cr2O3
Consider the freezing of liquid water at -10°C. For this process, what are the signs for DH, DS, and DG?
D
Consider the DG of four different combinations of DH and DS. Assume that both DH and DS are temperature independent.Which of these four processes is improbable at a low temperature, but becomes more probable as the temperature rises?
DH = (+) and DS = (+)
Consider the DG of four different combinations of DH and DS. Assume that both DH and DS are temperature independent.The process which is nonspontaneous at all values of temperaure is
DH = (+) and DS = (-)
Consider the DG of four different combinations of DH and DS. Assume that both DH and DS are temperature independent.Which processes are spontaneous at all temperature?
DH = (-) and DS = (+)
For endothermic reactions at constant pressure
DH > 0
Consider a closed flask containing a liquid and its vapor. Which statement is incorrect?
Evaporation and condensation will eventually cease after a constant pressure has been attained.
Two unlabeled Erlenmeyer flasks each contained 25.00 mL of solution at pH 4.00. Each flask was titrated with the same standardized NaOH solution. The volumes needed to reach the endpoint are listed in the table below. What claim can be made about the acids in flasks A and B?
Flask A was a strong acid because less titrant was needed to reach the endpoint.
In which of the following processes is there an increase in entropy?
H2O2(l) ® H2O(l) + 1/2 O2(g)
Which acid solution has a greater pH?
HA because it dissociates less than HX.
The mechanism below shows how ethanol
HA reacts with CH3CH2OH to produce CH2CH2 + H2O + HA
You are asked to make a buffered solution with a pH as close to 7.00 as possible by mixing equal volumes of 1.00 M solutions. Which of the following mixtures is the best choice?
HOCl (Ka = 3.5 ´ 10-8) and NaOCl
Consider protein structures:
Hydrogen bonds form between adjacent proteins.
According to the graph below, what chemical was added to the equilibrium mixture and how did the system respond?
Hydrogen was added and the concentration of nitrogen decreased.
Which is the stronger acid in each of the following pairs?
I. HClO3 II. H2Se III. H2SeO4
For each group of compounds listed, which is the strongest acid?I. HIO2, HIO3, HIO4II. H2Se, H2S, H3AsIII. HPO2, HClO2, HBrO2
I. HIO4, H2Se, HClO2
Which of the following reactions will have a positive value of DS°?I. Pb(s) + Cl2(g) " PbCl2(s)II. 2H2S(g) + 3O2(g) " 2H2O(g) + 2SO2(g)III. K2SO4(s) " 2K+(aq) + SO42-(aq)
III only
Consider the reaction represented by the equation: N2(g) + 3H2(g) 2NH3(g). What happens to the equilibrium position when an inert gas is added to this system (as represented above) at equilibrium?
If the container is rigid, nothing happens to the equilibrium position. If the container is fitted with a moveable piston, the equilibrium position shifts.
Which of the following is true about chemical equilibrium?
It is microscopically dynamic and macroscopically static.
Given the equilibrium constants for the following reactions:4Cu(s) + O2(g) 2Cu2O(s), K12CuO(s) Cu2O(s) + O2(g), K2what is K for the system2Cu(s) + O2(g) 2CuO(s)equivalent to?
K1 1/2 divided by k2
which of the following is ionic and contains both
KCN
which of the following is ionic and contains both sigma
KCN
The compound most likely to be ionic is
KF
A student dissolved 30 g of an unknown compound in 50 g of water at 39°C. What is the unknown compound?
KNO3
One way to produce nitric acid is through the Ostwald process. In the first reaction ammonia is oxidized to nitrogen monoxide.
Lower the temperature of the reaction and remove nitrogen monoxide as it is made.
For a laboratory investigation
Mg+2HCL--> MgCl2 + H2
Which is a correct explanation for why the reaction rate increases with increasing temperature?
More of the colliding particles have the activation energy.
Solve without using a calculator. A compound of nitrogen and oxygen is 63.64% by mass nitrogen. What is the empirical formula of this compound?
N2O
which of the following is incorrectly named
NO-3 Nitrite ion
Which of the following correctly ranks the species from weakest to strongest base?
NO31- < H2O < CLO21- < F1- < NH3 < CN1-
which equation for dissolving salt in water
Na2SO4 --> 2Na+ SO4
Which equation for dissolving this salt in water is written correctly?
Na2SO4 ® 2Na1+ + SO42-
Solve without using a calculator. A compound is analyzed and found to contain 1.30 moles of Na, 0.65 moles of Te, and 2.60 moles of O. What is the simplest formula of this compound?
Na2TeO4
Bromothymol blue is a chemical indicator that turns blue at pH values greater than 7. In which of these solutions would a blue color be observed if 2 drops of bromothymol blue were added? The concentration of each solution is 0.10 M. Ka for HC2H3O2(aq) = 1.8 ´ 10-5, Kb for NH3(aq) = 1.8 ´ 10-5
NaC2H3O2
The substances Neon, Sodium fluoride
Ne<CO<CH3NH2<NaF
The photoelectron spectra above show the energy required to remove a 1s electron from a nitrogen atom and from an oxygen atom. Which of the following statements best accounts for the peak in the upper spectrum being to the right of the peak in the lower spectrum?
Nitrogen atoms have a smaller nuclear charge than oxygen atoms.
The Ksp for BaF2 is 2.4 ´ 10-5. When 10 mL of 0.01 M NaF is mixed with 10 mL of 0.01 M Ba(NO3)2, will a precipitate form?
No, because Q is 1.25 ´ 10-7 and since it is less than Ksp no precipitate will form.
The Ksp of magnesium hydroxide is 8.9 ´ 10-12. If 0.0010 mole of Mg(OH)2 is added to 1.00 L of water, will it all dissolve? Do this without a calculator.
No, it will not all dissolve because Q is greater than K.
You have 100.0 mL of a solution of hydrochloric acid that has a pH of 3.00. You add 100.0 mL of water to this solution. What is the resulting pH of the solution?
None of the above is correct, but the pH must be greater than 3.00.
When placed in order of increasing ionization energy, what is the correct order for the species O, O1+, and O1-
O1-, O, O1+
Suppose a buffer solution is made from formic acid, HCHO2, and sodium formate, NaCHO2. What is the net ionic equation for the reaction that occurs when a small amount of sodium hydroxide is added to the buffer?
OH-(aq) + HCHO2(aq) ® CHO2-(aq) + H2O(l)
Electrons in atoms have quant
Observation A
From the following list of observations E- have wave properties
Observation D
Which of the following molecules has a dipole moment?
PF3 only
Consider the phosphoric acid equilibira.
PO4-3
Which of the following is the strongest base? (Kb for NH3 is 1.8 ´ 10-5, Ka2 for H2SO4 is 1.2 ´ 10-2, Ka3 for H3PO4 is 4.8 ´ 10-13)NH3, HSO4-, PO43-, or NO3-
PO43-
You may use a Periodic Table. In a phosphorus chloride
Polar, P, a partial positive
Given that the Ksp for calcium fluoride [CaF2] is 3.2 ´ 10-15, which of the following describes a solution that is 2.00 ´ 10-5 M NaF and 2.00 ´ 10-5 M Ca(NO3)2?
Q = 8 ´ 10-15 and there will be a precipitate formed
In a research project, a scientist adds 0.1 mole of HCN, 0.1 mole of H3O1+, and 0.1 mole of CN1- to water to make a total volume of 1 L. Will this reaction proceed to a greater extent in the forward direction or in the reverse direction?
Reverse; the K value is less than 1.
The lewis structure of which molecule requires resonance
SO2
Which of the species below, when dissolved in H2O, will not produce a basic solution?
SO2
Consider the reaction 2NO2(g) N2O4(g); DH° = -56.8 kJ and DS° = -175 J/K. In a container (at 298 K) N2O4(g) and NO2(g) are mixed with initial partial pressures of 2.4 atm and 0.42 atm, respectively. Which of the following statements is correct?
Some N2O4(g) will decompose into NO2(g).
What hybridization is predicted for NO3
Sp2
For a solution equimolar in HCN and NaCN, all these statements are true except?
The [H+] is larger than it would be if only the HCN was in solution.
The rate law if a particular reaction : False?
The actual value of K depends on concentration
Ten grams of Ca(OH)2(s) is added, with stirring, to 100 mL of water, producing a saturated solution with solid Ca(OH)2on the bottom of the beaker. Which is true?
The addition of 0.1 mole of solid Ca(NO3)2 will cause some additional Ca(OH)2 to form.
Which of the following is true about a system at equilibrium?
The concentration(s) of reactant(s) is constant over time.
As water is heated, its pH decreases. This means that:
The dissociation of water is an endothermic process.
what is the best explanation for the decrease in the first
The e- in n occupy the 2p
Considering the photoelectron specturm of carbon, which of the following best explains the large difference in binding energy between the peaks on the leaft and on the right?
The electrons generating the peak on the left are further from the nucleus and experience greater electron shielding.
What is the best explanation for the decrease in first ionization energy moving from N to O?
The electrons in N occupy the 2p orbitals singularly, whereas the electrons in one of the 2p orbitals of O are paired, thus increasing the electron-electron repulsions.
The acid strength of the oxyacids of chlorine is as follows:
The electrons in the H-O bond are pulled away from the hydrogen by the more electronegative oxygen, making the bond weaker. Additional oxygen atoms intensify this effect, making the H-O bond even weaker and increasing the degree of ionization.
Which of the following statements is true?
The equilibrium state is dynamic even though there is no change in concentrations.
The melting points of the compounds LiF, NaCl, KBr, and CsI exhibit the following trend:Melting point order: LiF > NaCl > KBr > CsI.Which of the following correctly explains this trend?
The greater radii of the larger ions results in smaller lattice energies, leading to lower melting points.
In general, the value of the equilibrium constant for a chemical reaction does NOT depend on
The initial amounts of reactants present.
Consider the dissolution of an ionic salt in water. Which of the following statements best explains why this process is considered a physical change?
The ionic salt can be recovered by evaporation of the water.
The fact that metals are conductive is best explained by which of the following statements?
The metal nuclei reside in a "sea" of delocalized electrons.
Aqueous solutions of NaCl and Na2CrO4 are mixed and they do not react. To this mixture an aqueous solution of AgNO3 is added (dropwise). At first, a white solid forms. As the AgNO3 solution continues to be added, a yellow solid begins to form. AgCl(s) is white in color and Ag2CrO4(s) is yellow. Which of the following is the most accurate conclusion based on these results?
The molar solubility of AgCl is less than the molar solubility of Ag2CrO4 because the white solid formed first.
Which of the following statements are true?
The pH of a neutral solution can be different from 7, depending on the conditions.
You have two buffered solutions. Buffered solution 1 consists of 5.0 M HOAc and 5.0 M NaOAc; buffered solution 2 is made of 0.050 M HOAc and 0.050 M NaOAc.How do the pHs of the buffered solutions compare?
The pH of buffered solution 1 is equal to that of buffered solution 2.
What will happen if a small amount of hydrochloric acid is added to a 0.1 M solution of HF?
The percent ionization of HF will decrease.
the expected electron configuration for copper should be AR
The photoelectron spectroscopy
A certain mass of neon gas is contained in a rigid steel container. The same mass of helium gas is added to this container. Which of the following best describes what happens? Assume the temperature is contant.
The pressure in the container more than doubles.
The removal of copper from metallic ores has been a challenge since ancient times. Strong heating of copper(II) carbonate results in the formation of copper(II) oxide.Although the decomposition of copper(II) oxide into copper metal and oxygen gas is not thermodynamically favorable under standard conditions, it may be made favorable by adding carbon to the mixture.Why is the overall process thermodynamically favorable?
The process involves coupling a very thermodynamically favorable reaction with one that is not thermodynamically favorable.
For a particular chemical reaction DH = 4.3 kJ and DS =-19 J/K. Under what temperature condition is the reaction spontaneous?
The reaction is not spontaneous at any temperature.
For the reaction, X + Y " A + B, DGo is -1324 kJ. Which one of the following statements is NOT valid concerning the reaction?
The reaction is not spontaneous at any temperature.
Solutions A and B are both clear and colorless. When Solution A is mixed with Solution B, the temperature of the mixture increases, and a yellow precipitate is observed. What can be concluded from these observations?
The reaction is thermodynamically favored (spontaneous) only at low temperatures
Under normal conditions, an iron nail rusts so slowly that the recation is not easily observed. What must be true?
The reaction occurs, but very slowly.
The mineral fluorite is the main source of calcium fluoride. CaF2 has a solubility of 2.2 ´ 10-4 M in pure water. Which is a correct explanation for what occurs when solid CaF2 is dissolved in an acidic solution, rather than in pure water?
The solubility increases because HF is a weak acid.
The equilibrium constant for the ionization of hypochlorous acid is 2.0 x 10-8. If a 1.0 M solution is at pH 2, what is the equilibrium condition of the system?HClO + H2O ↔ H3O1+ + ClO1-
The system will shift to the left to make reactants.
A sample of gas is heated from 35 to 70
The volume increases by a factor less 2
you are asked to make
The volume of the 1.00 M HCN must be greater than the volume of the 1.00 M NaCN.
Consider the chemical system CO + Cl2 COCl2; K = 4.6 x 109 L/mol.How do the equilibrium concentrations of the reactants compare to the equilibrium concentration of the product?
They are much smaller.
True or false: The species Cl- is not a good base in aqueous solution.
True. This is because water has a stronger attraction for protons than does Cl-.
A 0.10 M HCl solution may be titrated with two different bases: 0.10 M NaOH or 0.10 M Ca(OH2). Which statement best describes the volumes of the bases necessary to reach the equivalence point?
Twice as much NaOH is needed.
The table below shows the first eight
W and X
Using Hess' law and the equations below find ΔH° at 25°C for the oxidation of C2H5OH(l).
W-Y
At the normal body temperature of a human, 37°C, the equilibrium constant for the dissociation of water is higher than it is at 25°C, as shown in the equilibrium expression.
Water is neutral because the hydrogen and hydroxide ion concentrations are equal.
The solubility equations and Ksp values for two different chloride salts are shown below.
With NaCl, the forward reaction is favored. The relatively large equilibrium constant tells us that the products are favored.
the element X whose photoelectron spectrum
XCl5
The boiling point of noble gases are shown
Xe ha s more e- than the others
For which of the following can we directly compare their Ksp values to determine their relative solubilities?
ZnS and AgI
A certain buffer solution has a pH of 4.6. The weak acid used to make this solution, HA has a pKa of 3.2. Which statement best describes the relationship between the concentration of hydrogen ion, [H1+], and the concentration of A1-, [A1-]?
[H1+] < [A1-] because pH > pKa
Consider a solution consisting of the following two buffer systems: H2CO3 HCO3- + H+ pKa = 6.4 H2PO4- HPO42- + H+ pKa = 7.2At pH 6.4, which one of the following is true of the relative amounts of acid and conjugate base present?
[H2CO3] = [HCO3-] and [H2PO4-] > [HPO42-]
which of the following is not a valid resonance
[N with 2 dots on top and bottom-- H with 2 dots on top- N with 2 dots on top bottom and right] -
In which process is DS expected to be positive?
a spontaneous endothermic process at a constant temperature and pressure
Which item (a, b or c) in each of the three groups below has the lowest entropy?I. (a) 10 g ice (b) 10 g water vapor (c) 10 g liquid waterII. (a) 1 mole NaCl solid (b) 1 mol NaCl in 1 M aqueous solution (c) 1 mol molten NaClIII. (a) 1 mole C2H6(g), (b) 1 mole CH4(g), (c) 1 mol C3H8(g) all at 25 °C and 1 atm
aab
Given the following data (DHf, S°, respectively) for N2O4(l) -20. kJ/mol, 209.0 J/K mol, and N2O4(g) 10. kJ/mol,304.2 J/K mol. Above what temperature (in °C) is the vaporization of N2O4 liquid spontaneous?
above 42 degrees
Select the answer that best describes an aqueous solution made from each of the following substances:solid aluminum chloride (AlCl3)
acidic
Select the answer that best describes an aqueous solution made from each of the following substances:solid ammonium perchlorate (NH4ClO4) For NH4+, Ka = 5.6 ´ 10-10; for ClO4-, Kb » 10-21.
acidic
The type of bonding in a solid can be tested by placing the substance in water because
all are true
The type of bonding in a solid can be
all of these
Which of the following is true for a buffered solution?
all of these
which of the following names is incorrect
aluminum (III) oxide
As you go down the noble gas family on the periodic table, the boiling temperature increases. This trend is due mainly to
an increase in London dispersion forces.
Peak A is far to the left as peaks
are the innermost e- in the atom
When a sample of an unknown element
between 118 and 119
A solution is prepared by mixing 500 mL of 1 M HCl with 500 mL of 0.01 M HNO3. What is the pH of the solution? Do this without a calculator.
bwtn 0-1
DS is _______ for exothermic reactions and ______ for endothermic reactions.
cannot tell
A student attempted to dissolve a liquid ionic solution
chemical because 3 distinct
A student is trying to find
choose one set
For which process is DS negative?
compressing 1 mol Ne at constant temperature from 1.5 L to 0.5 L
Consider the following system at equilibrium at 25°C:PCl3(g) + Cl2(g) PCl5(g)for which DH° = -92.5kJ at 25°C.If the temperature of the system is raised, the ratio of the partial pressure of PCl5 to the partial pressure of PCl3 will
decrease
which of the following best describes BF3 and NF3
different geometry and different shapes
when a polar molecule dissolves in water
either hydrogen or dipole dipole
Consider a closed flask containing a liquid and its vapor
evaporation and condensation
The first electon affinity value for oxygen is
favorable (exothermic), unfav (endo)
For the equilibrium that exists in an aqueous solution of nitrous acid (HNO2, a weak acid), the equilibrium constant expression is:
h+no2/hno2
Using the information below, which of the following treatments might be highly effective for carbon monoxide poisoning, if started immediately?
have patient breathe pure oxy
In the titration of a weak acid, HA, with a sodium hydroxide solution of approximately the same concentration, the stoichiometric point occurs at pH = 9.5. Which of the following weak acid indicators would be best suited to mark the endpoint of this titration?
indicator A, Ka = 10-11
Iodine crystals dissolve in hexane
iodine, although non polar, momentary dipoles
When an ionic salt dissolves in water, the solute-solvent interaction is
ion-dipole forces
The properties of solids vary with their bonding. An example of this is shown by
ionic solids with strong electrostatic attractions called ionic bonds, which have high melting temperatures.
For a particular system at a particular temperature there ______ equilibrium constant(s) and there _______ equilibrium position(s).
is one; are infinite
1 Butanol would be expected
its the longer carbon chain
For the reaction , for which value of K is the concentration of the reactants greater than the concentration of the products?
k is less than 1
the noble gas xenon
low temp, high pressure
under what conditions does a gas behave more like
low temperature and high pressure
A chemical reaction is most likely to be spontaneous if it is accompanied by
lowering energy and increasing entropy
The stuctures of the amino acid, glycine are shown above. What is the predominant form of the amino acid at physiological pH 7.3?
more structure II than structure I
Doping of silicon is achieved by
n-type semi bv phosphorus atoms
In which of the following electron trans.
n=4 to n=3
Predict the sign of DS° for each of the following processes:I. 2 K(s) + Cl2(g) " 2 KCl(s)II. CH4(g) " C(s) + 2 H2(g)III. CaCO3(s) " CaO(s) + CO2(g)
negative, positive, positive
A sample of neon gas is contained
neon is 1.5x greater
Select the answer that best describes an aqueous solution made from each of the following substances:solid sodium nitrate (NaNO3)
neutral
Which of the following would produce a basic aqueous solution?
none
In which of the following pairs is the substance with the HIGHER entropy listed first?I. NaCl(s), NaCl(aq)II. CO(g), CO2(g)III. 1 mole of H2(g) at 25°C; 1 mole of H2(g) at 50°C
none of them
From the following list of observations wave characteristics
observation D
Based on molecular structure and intermolecular forces, which of these substances would you predict to have the greatest viscosity?
one with OH at bottom
The autoionization of water is an endothermic process. How would the pH of pure water change if the water was at 100°C?
pH would decrease because equilibrium shifts towards [H3O1+] and [OH1-].
which of the following pairs is incorrect
phosphorus pentoxide, P2O5
The following reaction was determined to be elementary: A + B ® C What is the overall order of the reaction and the units of the rate constant,k?
second order, L/(mol x time)
At constant pressure, the following reaction 2NO2(g) ® N2O4(g) is exothermic. The reaction (as written) is
spontaneous at low temperatures, but not high temperatures
Strong acids do not make good buffered solutions because
strong acids dissociate completely and the equilibrium lies far to the right.
Name the element whose mass spectrum is shown above.
sulfur
In a molecule in which the central atom exhibits sp3 hybrid orbitals, the electron pairs are directed toward the corners of a
tetrahedral
An example of an alloy is shown in the diagram below
the alloy has lower malleability and higher
As water is heated, its pH decreases. This means that: diff one
the dissociation of water is an endothermic process.
What is the best explanation for the decrease in first ionization energy moving from Be to B?
the electrons in the Be are located in the 2s subshell, which is closer to the nucleus and thurs harder to remove than th 2p electrons in B.
A reaction takes place within a system. As a result, the entropy of the system decreases. Which of the following statements must be true?
the entropy of surroundings increase
In deciding which of two acids is the stronger, one must know:
the equilibrium constant of each acid
Two salts, AX and BX2, have identical Ksp values at a given temperature. We can say
the molar solubility of AX is less than that of BX2.
The correct orbital diagram for the valence electrons of silicon is
the pic that has three lines filled up. oneup down other two are just upup
At a certain temperature, the synthesis of ammonia gas from nitrogen and hydrogen gases, shown as , has a value for K of 3.0 x 10-2. If [H2]o = [N2]o = 0.10 M and [NH3]o = 0.20 M,
the reaction would shift toward the N2 and the H2.
Small drops of water tend to bead up because of
the resistance to increased surface area.
A buffer can maintain pH upon addition of small amounts of a strong base because
the strong base is balanced by the weak acid and conjugate base in the buffer.
Consider four 100.0-g samples of water, each in a separate beaker at 25.0°C. Into each beaker you drop 10.0 g of a different metal that has been heated to 95.0°C. Assuming no heat loss to the surroundings, which water sample will have the lowest final temperature? Solve without using a calculator.
the water to which you have added lead (Cp = 0.14 J/°C · g)
A visible light spectrometer would best
to determine the concentration
CS2(g) + 3Cl2(g) CCl4(g) + S2Cl2(g)At a given temperature, the reaction above is at equilibrium when [CS2] = 0.050 M, [Cl2] = 0.25 M, [CCl4] = 0.15 M, and [S2Cl2] = 0.35 M. What would be the direction of the reaction when the reactants and products have the following concentrations: CS2 = 0.15 M, Cl2 = 0.18 M, CCl4 = 0.29 M, and S2Cl2 = 0.21 M?
to the left
The predicted molecular shape of PH3 according to the VSEPR theory is
trigonal pyramidal
Consider a 0.70 M solution of HOCl. If the molarity was decreased to 0.3 M, which of the following statements would be true?
two of these
The hydrogen halides (HF, HCl, HBr, and HI) are all polar molecules. The strength of the acid each forms in water is based on which of the following?
two of these
The question below refers to the following system: Co(H2O)62+ + 4 Cl- CoCl42- + 6H2O (pink) (blue) When cobalt(II) chloride is added to pure water, the Co2+ions hydrate. The hydrated form then reacts with the Cl-ions to set up the equilibrium shown here.Which statement below describes the change that the system will undergo if hydrochloric acid is added?
two of these
Why does chlorine gain an E-
two of these
Why does chlorine gain an electron to become a chloride ion?
two of these
When a mixture of oil and water sits undisturbed, two distinct layers will form. This is because
two of these are true.
Why do mineral deposits accumulate
when the water vaporizes
Consider the dissociation of hydrogen: H2(g) 2H(g)One would expect that this reaction:
will be spontaneous at high temperatures
Consider this system: 3.5 ´ 102 mL of 3.2 M Pb(NO3)2 and 2.0 ´ 102 mL of 0.020 M NaCl are added together. Ksp for the lead chloride is 1.6 ´ 10-5.Will precipitation occur?
yee
Methyl orange is an indicator with a Ka of 1 ´ 10-4. Its acid form, HIn, is red, while its base form, In-, is yellow. At pH 6.0, the indicator will be
yellow
