1. / Which of the following is equal for the forward and reverse reactions at equilibrium?
A) / concentration
B) / rates
C) / rate constants
2. / All chemical equilibria are _____ in nature.
A) / dynamic
B) / equal
C) / static
D) / kinetic
3. / An example of a physical equilibrium is _____.
A)
B)
C)
D)
4. / Which of the following is not a physical equilibrium?
A) / melting
B) / allotropic transformation
C) / vaporization
D) / rusting
5. / An example of heterogeneous equilibrium is _____.
A)
B)
C) / Enzyme-catalyzed reactions
6. / Which of the following statements is always correct?
A) / chemical equilibria are homogeneous
B) / physical equilibria are homogeneous
C) / physical equilibria are heterogeneous
D) / chemical equilibria are heterogeneous
7. / The expression for Kp for the reaction
is _____.
A)
B) / P
C) / / P
D) / · P
8. / The expression for Kp for the reaction
is _____.
A) / 2P + P
B) / P2· P
C) / P + P
D) / 2P / P
9. / The equilibrium constant Kp is not applicable for the reaction _____.
A)
B)
C)
D)
10. / The equilibrium constant Kc for the reaction is given by _____.
A)
B)
C)
D)
11. / The equation relating Kp and Kc is _____.
A) / Kp = Kc (RT)Dn
B) / Kp = Kc RTDn
C) / Kc = Kp RTDn
D) / Kc = Kp (RT)Dn
12. / Kp will be equal to Kc if _____.
A) / Dn = 1
B) / Dn = 0
C) / RT = 0
D) / Dn = ¥
13. / Kp will be less than Kp if _____.
A) / DH = negative
B) / Dn = positive
C) / Dn = negative
D) / Dn = 0
14. / The equilibrium constants for the reactions
and
are x and y, respectively. The equilibrium constant for the reaction
is _____.
A)
B) / x + y
C) / x – y
D) / xy

Use the following to answer questions 15-16:

The equilibrium constant for the reaction

is x.

15. / The equilibrium constant for the reaction
is _____.
A) / –x
B) / x
C) / 1/x
D) / 2x
16. / The equilibrium constant for the reaction is _____.
A) / 2x
B) / x
C) / x/2
D) / x2
17. / The equilibrium constant for the reaction
is 4.17 ´ . The equilibrium constant for the reaction is
A) / –4.17 ´
B) / 4.17 ´ 1031
C) / 2.40 ´ 1030
D) / 2.40´ 10-33
18. / The number of moles of H2, S2, and H2S present at the equilibrium for the reaction
are 2.50, 1.35 ´ 10-5 and 8.70 moles respectively in a 12 L flask. The equilibrium constant, Kc for the reaction is _____.
A) / 1.08 ´ 107
B) / 1.08 ´ 10-7
C) / 5.6 ´ 103
D) / 7.2 ´ 10-5
19. / Kc for the reaction
is 2.24 ´ 1022 at 1273 ºC. Kp for the reaction at the same temperature is _____.
A) / 7.16 ´ 10-18
B) / 1.76 ´ 1020
C) / 5.12 ´ 10-15
D) / 3.12 ´ 1019
20. / The equilibrium partial pressures of N2, O2 and NO in the reaction
are 0.15, 0.33 and 0.050 atm, respectively at 2200°C. The value of Kp for the reaction is _____.
A) / 5.1
B) / 0.51
C) / 51
D) / 0.051
21. / The equilibrium concentrations of NH3, N2 and H2 are 0.25 M, 0.11 M and 1.91 M, respectively. The equilibrium constant Kc for the reaction is _____.
A) / 0.082
B) / 8.2 ´ 10-3
C) / 8.2
D) / 0.82
22. / The equilibrium constant, Kc, for the reaction
is 0.082. What is Ka for
A) / 0.164
B) / 0.041
C) / 0.29
D) / 1.64
23. / The equilibrium constant, Kc , for the reaction
is 3.8 ´ 10-5 at 727°C. The value of Kp for the equilibrium
at the same temperature is _____.
A) / 648
B) / 320
C) / 32.0
D) / 6.48
24. / The equilibrium pressure for the reaction
is 0.105 atm at 350°C. Kp for the reaction is _____.
A) / 0.105
B) / 0.210
C) / 1.05
D) / 10.5
25. / Kp for the reaction
at 350oC is 0.105. Kc for the reaction at the same temperature is _____.
A) / 4.21 ´ 103
B) / 0.105
C) / 3.05 ´ 10-4
D) / 2.05 ´ 10-3
26. / The equilibrium constant, Kp, for the reaction
is 1.05 at 250°C. The reaction is started with PCl5, PCl3 and Cl2 at 0.177, 0.223 and 0.111 atm at 250°C. When the reaction comes to equilibrium, the pressure of _____.
A) / PCl3 must have decreased
B) / Cl2 must have decreased
C) / PCl5 must have decreased
D) / PCl5 must have increased
27. / Starting with only the solid, the total pressure of NH3 and CO2 was found to 0.363 atm for the equilibrium at 40°C. The equilibrium constant, Kp is
A) / 7.1 ´ 10-3
B) / 2.5 ´ 10-2
C) / 5.3 ´ 10-4
D) / 3.6 ´ 10-6
28. / 1.05 moles of Br2 in a 0.980 L container undergo 1.2% dissociation. The equilibrium constant, Kc for the reaction is _____.
A) / 2.5 ´ 10-5
B) / 1.8 ´ 10-3
C) / 6.2 ´ 10-4
D) / 5.9 ´ 10-6
29. / Kp = Kc for the reaction _____.
A)
B)
C)
D)
30. / 3.00 ´ 10-2 mol of phosgene gas, COCl2, was heated in a 1.50 L container at 800 K. At equilibrium the pressure of CO was found to be 0.497 atm. The equilibrium constant, Kp for the reaction is _____.
A) / 3.30
B) / 9.80
C) / 2.75
D) / 5.61
31. / The equilibrium constant, Kp for the reaction
at 2200°C is 0.051. The equilibrium constant, Kc for the same reaction is _____.
A) / 0.102
B) / 0.051
C) / 2.5 ´ 10-3
D) / 1.02 ´ 104

Use the following to answer questions 32-33:

At equilibrium, nitrosyl bromide in the reaction

is 34% dissociated at 25°C and the total pressure is 0.25 atm.

32. / The value of Kp for the reaction is _____.
A) / 9.6 ´ 10-3
B) / 1.39 ´ 10-5
C) / 3.8 ´ 10-4
D) / 6.7 ´ 10-6
33. / The value of Kc for the above reaction is _____.
A) / 1.6 ´ 10-6
B) / 2.7 ´ 10-5
C) / 3.9 ´ 10-4
D) / 4.5 ´ 10-7
34. / 2.50 mole of NOCl was heated in a 1.50 L vessel at 400°C.At equilibrium it was found that 28.0% of the NOCl had dissociated. The equilibrium constant, Kc of the reaction is _____.
A) / 0.0353
B) / 3.53 ´ 102
C) / 3.53 ´ 10-4
D) / 3.53
35. / The ionization constants Kc' and Kc” for
were found to be 9.5 ´ 10-8 and 1.0 ´ 10-19 respectively. The equilibrium constant for the reaction
is _____.
A) / 9.5 ´ 10-8
B) / 1.0 ´ 10-19
C) / 9.5 ´ 10-27
D) / 1.05 ´ 10-12
36. / The equilibrium constant, Kc = 4.0 × 10-6 for the reaction
.
If the equilibrium constant, Kc= 6.5 ´ 10-2 for the reaction
,
the equilibrium constant for
is _____.
A) / 4.0´ 10-6
B) / 6.1 ´ 10-5
C) / 1.6 ´ 104
D) / 6.5 ´ 10-2

Use the following to answer questions 37-38:

The following equilibrium constants were measured for the reactions:

37. / The equilibrium constant for the reaction
is _____.
A) / xy
B) / x + y
C) / xy2
D) / x + y2
38. / The equilibrium constants K1 and K2 for the reactions above are
1.3 ´ 1014 and 6.0 ´ 10-3, respectively. The equilibrium constant for the reaction
is _____.
A) / 4.7 ´ 109
B) / 1.0 ´ 1014
C) / 1.0 ´ 1026
D) / 3.6 ´ 1018
39. / The equilibrium constants K1 K2 and K3 for the reactions below are
K1 = 4.2 ´ 1052
K2 = x
K3 = 5.6 ´ 1023.
The value of K2 is _____.
A) / 9.8 ´ 1028
B) / 9.8 ´ 10128
C) / 6.7 ´ 1012
D) / 2.6 ´ 1075
40. / The equilibrium constant in terms of rate constants for the forward reaction, kf, and the reverse reaction, kr, is given as _____.
A)
B) / K = kf + kr
C)
D) / K = kf kr
41. / The concentration of H+ in pure water at 25°C is _____.
A) / 10-14 M
B) / 10-7 M
C) / 10-10 M
D) / 10-8 M
42. / The equilibrium constant of a reaction is 12.6. If the rate constant of the reverse reaction is 5.1 ´ 10-2, the rate constant for the forward reaction is _____.
A) / 0.32
B) / 0.16
C) / 0.64
D) / 0.08
43. / Which of the following statements can be correct with respect to reaction quotient, Q and equilibrium constant, K?
A) / Q < K
B) / Q = K
C) / Q > K
D) / all the above
44. / The value of Kc for the equilibrium
is 5.6 ´ 104 350°C. The initial pressures of SO2 and O2 in a mixture are 0.350 atm and 0.762 atm. The total pressure at equilibrium will be _____ atm.
A) / less than 0.350
B) / less than 0.741
C) / less than 1.112
D) / equal to 1.112
45. / The value of Kc for the reaction is 1.2 . The reaction is started with [H2 ]0 = 0.76 M, [N2]0 = 0.60 M and [NH3]0= 0.48 M. Which of the following is correct as the reaction comes to equilibrium?
A) / The concentration of N2will increase
B) / The concentration of H2will decrease
C) / The concentration of NH3will decrease
D) / The concentration of both N2and H2will increase

Use the following to answer questions 46-48:

For the reaction

Kc = 0.534 at 700°C

46. / Calculate the number of moles of H2 present at equilibrium if a mixture of 0.300 moles of CO and 0.300 moles of H2O is heated to 700°C in a 10.0 L container.
A) / 0.432 mol
B) / 0.273 mol
C) / 0.577 mol
D) / 0.173 mol
47. / Which statement is correct with respect to the above equilibrium when 0.30 moles of CO and 0.30 moles of H2O are heated to 700°C and allowed to reach equilibrium.
A) / [H2O] = [CO2]
B) / [CO2] = [CO]
C) / [H2O] = [CO]
D) / [H2O] = [H2]
48. / Which of the following statements is correct?
A) / All concentrations are equal
B) / Kp = Kc
C) / Kp < Kc
D) / Kp > Kc
49. / Kp is 158 for the equilibrium
Starting with NO2 (g) only, the partial pressure of O2 at equilibrium is 0.25 atm. Calculate the partial pressure of NO2 at equilibrium.
A) / 0.020 atm
B) / 0.20 atm
C) / 3.1 atm
D) / 0.035atm
50. / The partial pressure of NO in the above equilibrium is _____ atm.
A) / 0.125
B) / 0.50
C) / 0.25
D) / 0.02
51. / The equilibrium constant Kc for the reaction is 2.18 ´ 106. Starting with 3.20 moles of HBr in a 12.0L container, the concentration of HBr at equilibrium is _____.
A) / 0.167 M
B) / 0.0267 M
C) / 1.6 M
D) / 0.267 M
52. / Kc is 3.8 ´ 10-5 at 1000K for the equilibrium
Starting with 0.0456 moles of I2 in a 2.30 L flask, at 1000 K, the equilibrium concentration of I2 at is:
A) / 1.94 M
B) / 0.0194 M
C) / 0.12 M
D) / 0.012 M

Use the following to answer questions 53-54:

Kc for the reaction is 4.63 ´ 10-3 at 527°C .

53. / Starting with pure phosgene, COCl2, at 0.760 atm, the equilibrium partial pressure of CO is _____.
A) / 0.352 atm
B) / 0.0416 atm
C) / 0.0352 atm
D) / 0.416 atm
54. / Starting with pure phosgene, COCl2, at 0.760 atm, the equilibrium partial pressure of COCl2 is _____.
A) / 0.173 atm
B) / 0.204 atm
C) / 0.302 atm
D) / 0.408 atm
55. / What is the value of Kc for the reaction when the equilibrium concentrations of CO, H2, CO2 and H2O are 0.050 M, 0.045 M, 0.086 M and 0.040 M respectively?
A) / 0.074
B) / 0.52
C) / 0.063
D) / 0.24

Use the following to answer questions 56-57:

The equilibrium constant Kp for the reaction is 1.52 and the total pressure at equilibrium is 4.50 atm.

56. / The equilibrium partial pressure of CO is _____ atm.
A) / 0.86
B) / 1.62
C) / 1.96
D) / 1.31
57. / The equilibrium partial pressure of CO2 is _____ atm.
A) / 2.54 atm
B) / 0.98 atm
C) / 1.27 atm
D) / 0.72 atm

Use the following to answer questions 58-60:

The equilibrium constant, Kc for the reaction is 4.2. Initially 0.80 mole of H2 and 0.80 mole CO2 are placed in a 5.0 L flask.

58. / The concentration of H2 at equilibrium is _____.
A) / 0.054 M
B) / 0.025 M
C) / 0.15 M
D) / 0.029 M
59. / At equilibrium, the concentration of H2 is equal to the concentration of _____.
A) / H2O
B) / CO
C) / CO2
D) / H2O + CO2
60. / The concentration of CO at equilibrium is _____.
A) / 0.22M
B) / 0.056M
C) / 0.021M
D) / 0.11M
61. / Le Châtelier's principle can help to predict how to maximize _____.
A) / Reaction yield
B) / Equilibrium constant
C) / Temperature
D) / Rate constant
62. / Which can alter the value of the equilibrium constant?
A) / Catalyst
B) / Concentration
C) / Pressure
D) / Temperature
63. / The equilibrium position of the reaction
can be shifted in the forward direction by _____.
A) / Removing SO2
B) / Adding Cl2
C) / Removing Cl2
D) / Removing SO2 and Cl2

Use the following to answer questions 64-65:

The equilibrium constant Kc for the equilibrium

is x.

64. / The equilibrium constant for the reaction
is _____.
A) / x/2
B) / x1/2
C) / x2
D) / 2x
65. / The equilibrium constant for the reaction is _____.
A) / x2
B)
C) / x–2
D) / –2x
66. / Which of the following equilibria is not affected by pressure?
A)
B)
C)
D)
67. / The equilibrium
, can be shifted toward more product formation by _____. DH = 92.5 kJ.
A) / Increasing temperature
B) / Increasing pressure
C) / Decreasing temperature
D) / Increasing the concentration PCl3
68. / The equilibrium
can shifted to the reactant side by _____. DH = –198.2 kJ
A) / Decreasing temperature
B) / Decreasing volume
C) / Decreasing pressure
D) / Increasing the concentration of SO2
69. / The equilibrium pressure of NO2 in the equilibrium is 1.56 atm. Its pressure on the addition of a catalyst will be _____.
A) / 1.06 atm
B) / 0.75 atm
C) / 1.56 atm
D) / 2.71 atm
70. / The position of the equilibrium can be shifted to the left by the addition of _____ at constant pressure.
A) / CO
B) / He
C) / O2
D) / KCl
71. / The addition of He to the equilibrium at constant volume _____.
A) / Shifts the equilibrium to the left
B) / Increases Kc
C) / Shifts the equilibrium to the right
D) / Has no effect
72. / Which of the following will shift the equilibrium to the right?
A) / Decrease of temperature
B) / Addition of KCl
C) / Addition of CO2
D) / Addition of NaOH solution
73. / The equilibrium can be shifted to the right by _____.
A) / increasing temperature
B) / decreasing pressure
C) / removing some CO2
D) / all of the above

Use the following to answer questions 74-76: