Question 1

For which of the following reactions will ∆n = 1?

Accepted Answer

A)  H2(g) + I2(g) ⇌ 2HI(g) 
B)  CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g) 
C)  N2O4(g) ⇌ 2NO2(g) 
D)  CO(g) + 2H2(g) ⇌ CH3OH(g) 
E)  N2(g) + 3H2(g) ⇌ 2NH3(g) 
A)  H2(g) + I2(g) ⇌ 2HI(g) 
B)  CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g) 
C)  N2O4(g) ⇌ 2NO2(g) 
D)  CO(g) + 2H2(g) ⇌ CH3OH(g) 
E)  N2(g) + 3H2(g) ⇌ 2NH3(g) C

Question 2

The decomposition of ammonia is 2NH3(g) → N2(g) + 3H2(g). If Kp is 1.5 × 103 bar2 at 400 °C, what is the partial pressure of ammonia at equilibrium when the partial pressure of N2(g) is 0. 10 bar and that of H2(g) is 0.15 bar?

Accepted Answer

A)  2.2 × 10-7 bar 
B)  4.7 × 10-4 bar 
C)  2.1 × 103 bar 
D)  4.4 × 106 bar 
A)  2.2 × 10-7 bar 
B)  4.7 × 10-4 bar 
C)  2.1 × 103 bar 
D)  4.4 × 106 bar B

Question 3

Give the direction of the reaction if K >> 1.

Accepted Answer

A)  The forward reaction is favoured. 
B)  The reverse reaction is favoured. 
C)  Neither direction is favoured. 
D)  If the temperature is raised, then the forward reaction is favoured. 
E)  If the temperature is raised, then the reverse reaction is favoured. 
A)  The forward reaction is favoured. 
B)  The reverse reaction is favoured. 
C)  Neither direction is favoured. 
D)  If the temperature is raised, then the forward reaction is favoured. 
E)  If the temperature is raised, then the reverse reaction is favoured. A

Question 4

The following reaction is exothermic. Which change will shift the equilibrium to the left? 2SO2(g) + O2(g) ⇌ 2SO3(g)

Accepted Answer

A)  raising the temperature 
B)  removing SO3 
C)  adding O2 
D)  increasing the pressure 
E)  adding SO2 
A)  raising the temperature 
B)  removing SO3 
C)  adding O2 
D)  increasing the pressure 
E)  adding SO2

Question 5

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. 2SO2(g) + O2(g) ⇌ 2SO3(g) K = 1.7 × 106
SO3(g) ⇌ 1/2 O2(g) + SO2(g) K = ?

Accepted Answer

A)  3.4 × 102 
B)  8.5 
C)  1.3 × 103 
D)  1.2 × 10-6 
E)  7.7 × 10-4 
A)  3.4 × 102 
B)  8.5 
C)  1.3 × 103 
D)  1.2 × 10-6 
E)  7.7 × 10-4

Question 6

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. H2(g) + Br2(g) ⇌ 2HBr(g) K = 3.8 × 104
4HBr(g) ⇌ 2H2(g) + 2Br2(g) K = ?

Accepted Answer

A)  1.9 × 104 
B)  5.1 × 10-3 
C)  2.6 × 10-5 
D)  6.9 × 10-10 
E)  1.6 × 103 
A)  1.9 × 104 
B)  5.1 × 10-3 
C)  2.6 × 10-5 
D)  6.9 × 10-10 
E)  1.6 × 103

Question 7

Consider the following reaction at equilibrium. What effect will increasing the temperature have on the system? Fe3O4(s) + CO(g) ⇌ 3FeO(s) + CO2(g) ΔrH°= +35.9 kJ

Accepted Answer

A)  The reaction will shift in the direction of reactants. 
B)  The equilibrium constant will increase. 
C)  The equilibrium constant will decrease. 
D)  No effect will be observed. 
E)  The reaction will shift in the direction of products. 
A)  The reaction will shift in the direction of reactants. 
B)  The equilibrium constant will increase. 
C)  The equilibrium constant will decrease. 
D)  No effect will be observed. 
E)  The reaction will shift in the direction of products.

Question 8

Determine the value of Kp for the following reaction if the equilibrium concentrations are as follows: P(CO)eq = 6.8 × 10-11 atm, P(O2)eq = 1.3 × 10-3 atm, P(CO2)eq = 0.041 atm. 2 CO(g) + O2(g) ⇌ 2 CO2(g)

Accepted Answer

A)  3.6 × 10-21 atm-1 
B)  2.8 × 1020 atm-1 
C)  4.6 × 1011 atm-1 
D)  2.2 × 10-12 atm-1 
E)  3.6 × 10-15 atm-1 
A)  3.6 × 10-21 atm-1 
B)  2.8 × 1020 atm-1 
C)  4.6 × 1011 atm-1 
D)  2.2 × 10-12 atm-1 
E)  3.6 × 10-15 atm-1

Question 9

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g). C2H4(g) + H2O(g) ⇌ C2H5OH(g) Kc = 9.0 × 103 M-1
[C2H4]eq = 0.015 mol L-1 [C2H5OH]eq = 1.69 mol L-1

Accepted Answer

A)  9.9 × 10-7 mol L-1 
B)  80. mol L-1 
C)  1.0 mol L-1 
D)  1.68 mol L-1 
E)  0.013 mol L-1 
A)  9.9 × 10-7 mol L-1 
B)  80. mol L-1 
C)  1.0 mol L-1 
D)  1.68 mol L-1 
E)  0.013 mol L-1

Question 10

The reaction below has a Kc value of 61 M-2. What is the value of Kp for this reaction at 500 K? N2(g) + 3H2(g) ⇌ 2NH3(g)

Accepted Answer

A)  15 bar-2 
B)  61 bar-2 
C)  28 bar-2 
D)  3.6 × 10-2 bar-2 
E)  1.9 × 10-2 bar-2 
A)  15 bar-2 
B)  61 bar-2 
C)  28 bar-2 
D)  3.6 × 10-2 bar-2 
E)  1.9 × 10-2 bar-2

Question 11

Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? 2H2S(g) + 3O2(g) ⇌ 2H2O(g) + 2SO2(g)

Accepted Answer

A)  The reaction will shift in the direction of products. 
B)  No effect will be observed. 
C)  The reaction will shift in the direction of reactants. 
D)  The equilibrium constant will decrease. 
E)  The equilibrium constant will increase. 
A)  The reaction will shift in the direction of products. 
B)  No effect will be observed. 
C)  The reaction will shift in the direction of reactants. 
D)  The equilibrium constant will decrease. 
E)  The equilibrium constant will increase.

Question 12

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction:   (g) +   (g) →   (g) An equilibrium mixture at 450 K contains   = 0.124 bar,   = 0.157 bar, and   = 1.30 bar. What is the value of Kp at this temperature?

Accepted Answer

A)  66.8 bar-1 
B)  4.63 bar-1 
C)  2.53 × 10-2 bar-1 
D)  1.50 × 10-2 bar-1 
E)  1.03 bar-1 
A)  66.8 bar-1 
B)  4.63 bar-1 
C)  2.53 × 10-2 bar-1 
D)  1.50 × 10-2 bar-1 
E)  1.03 bar-1

Question 13

Give the direction of the reaction if K << 1.

Accepted Answer

A)  The forward reaction is favoured. 
B)  The reverse reaction is favoured. 
C)  Neither direction is favoured. 
D)  If the temperature is raised, then the forward reaction is favoured. 
E)  If the temperature is raised, then the reverse reaction is favoured. 
A)  The forward reaction is favoured. 
B)  The reverse reaction is favoured. 
C)  Neither direction is favoured. 
D)  If the temperature is raised, then the forward reaction is favoured. 
E)  If the temperature is raised, then the reverse reaction is favoured.

Question 14

Consider the following reaction and its equilibrium constant: I2(g) ⇌ 2I(g) Kp = 0.209 atm
A reaction mixture contains 4.0 atm I2 and 0.5 atm I. Which of the following statements is TRUE concerning this system?

Accepted Answer

A)  The reaction will shift in the direction of reactants. 
B)  The reaction quotient will increase. 
C)  The reaction will shift in the direction of products. 
D)  The equilibrium constant will decrease. 
E)  The system is at equilibrium. 
A)  The reaction will shift in the direction of reactants. 
B)  The reaction quotient will increase. 
C)  The reaction will shift in the direction of products. 
D)  The equilibrium constant will decrease. 
E)  The system is at equilibrium.

Question 15

Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows: [N2]eq = 1.5 mol L-1, [H2]eq = 1.1 mol L-1, [NH3]eq = 0.47 mol L-1. N2(g) + 3H2(g) ⇌ 2NH3(g)

Accepted Answer

A)  3.5 M-2 
B)  0.28 M-2 
C)  9.1 M-2 
D)  0.11 M-2 
E)  0.78 M-2 
A)  3.5 M-2 
B)  0.28 M-2 
C)  9.1 M-2 
D)  0.11 M-2 
E)  0.78 M-2

Question 16

Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows: [H2]eq = 0.14 mol L-1, [I2]eq = 0.39 mol L-1, [HI]eq = 1.6 mol L-1. H2(g) + I2(g) ⇌ 2HI(g)

Accepted Answer

A)  2.1 × 10-2 
B)  29 
C)  47 
D)  3.4 × 10-2 
E)  8.7 × 10-2 
A)  2.1 × 10-2 
B)  29 
C)  47 
D)  3.4 × 10-2 
E)  8.7 × 10-2

Question 17

For the following reaction, what is △n required in the conversion of Kc to Kp? 2Na(s) + 2H2O(l) ⇌ 2NaOH(aq) + H2(g)

Accepted Answer

A)  3 
B)  -1 
C)  -2 
D)  2 
E)  1 
A)  3 
B)  -1 
C)  -2 
D)  2 
E)  1

Question 18

Express the equilibrium constant for the following reaction:   + 6CN-(aq) ⇌   + 6H2O(l)

Accepted Answer

A)  Kc =   
B)  Kc =   
C)  Kc =   
D)  Kc =   
E)  Kc =   
A)  Kc =   
B)  Kc =   
C)  Kc =   
D)  Kc =   
E)  Kc =

Question 19

Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation:   At 250° 0. 125 mol L-1 PCl5 is added to the flask. If Kc = 1.80 mol L-1, what are the equilibrium concentrations of each gas?

Accepted Answer

A)  [PCl5] = 0.0 0765 mol L-1, [PCl3] = 0. 117 mol L-1, and [Cl2] = 0. 117 mol L-1 
B)  [PCl5] = 0. 0625 mol L-1, [PCl3] = 0. 335 mol L-1, and [Cl2] = 0. 335 mol L-1 
C)  [PCl5] = 1.80 mol L-1, [PCl3] = 1.80 mol L-1, and [Cl2] = 1.80 mol L-1 
D)  [PCl5] = 3.96 mol L-1, [PCl3] = 3.83 mol L-1, and [Cl2] = 3.83 mol L-1 
A)  [PCl5] = 0.0 0765 mol L-1, [PCl3] = 0. 117 mol L-1, and [Cl2] = 0. 117 mol L-1 
B)  [PCl5] = 0. 0625 mol L-1, [PCl3] = 0. 335 mol L-1, and [Cl2] = 0. 335 mol L-1 
C)  [PCl5] = 1.80 mol L-1, [PCl3] = 1.80 mol L-1, and [Cl2] = 1.80 mol L-1 
D)  [PCl5] = 3.96 mol L-1, [PCl3] = 3.83 mol L-1, and [Cl2] = 3.83 mol L-1

Question 20

At a certain temperature, nitogen and hydrogen react to form ammonia: N2(g) + 3 H2(g) ⇌ 2 NH3(g)
When initial amounts of N2, H2, and NH3 are mixed, the concentration of NH3 increases. Which statement below is TRUE?

Accepted Answer

A)  Kc c > Q 
C)  Kc = Q 
D)  Kc = Q = 0 
A)  Kc c > Q 
C)  Kc = Q 
D)  Kc = Q = 0

Exam 14: Chemical Equilibrium

For which of the following reactions will ∆n = 1?

The decomposition of ammonia is 2NH3(g) → N2(g) + 3H2(g). If Kp is 1.5 × 103 bar2 at 400 °C, what is the partial pressure of ammonia at equilibrium when the partial pressure of N2(g) is 0. 10 bar and that of H2(g) is 0.15 bar?

Give the direction of the reaction if K >> 1.

The following reaction is exothermic. Which change will shift the equilibrium to the left? 2SO2(g) + O2(g) ⇌ 2SO3(g)

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. 2SO2(g) + O2(g) ⇌ 2SO3(g) K = 1.7 × 106 SO3(g) ⇌ 1/2 O2(g) + SO2(g) K = ?

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. H2(g) + Br2(g) ⇌ 2HBr(g) K = 3.8 × 104 4HBr(g) ⇌ 2H2(g) + 2Br2(g) K = ?

Consider the following reaction at equilibrium. What effect will increasing the temperature have on the system? Fe3O4(s) + CO(g) ⇌ 3FeO(s) + CO2(g) ΔrH°= +35.9 kJ

Determine the value of Kp for the following reaction if the equilibrium concentrations are as follows: P(CO)eq = 6.8 × 10-11 atm, P(O2)eq = 1.3 × 10-3 atm, P(CO2)eq = 0.041 atm. 2 CO(g) + O2(g) ⇌ 2 CO2(g)

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g). C2H4(g) + H2O(g) ⇌ C2H5OH(g) Kc = 9.0 × 103 M-1 [C2H4]eq = 0.015 mol L-1 [C2H5OH]eq = 1.69 mol L-1

The reaction below has a Kc value of 61 M-2. What is the value of Kp for this reaction at 500 K? N2(g) + 3H2(g) ⇌ 2NH3(g)

Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? 2H2S(g) + 3O2(g) ⇌ 2H2O(g) + 2SO2(g)

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction: (g) + (g) → (g) An equilibrium mixture at 450 K contains = 0.124 bar, = 0.157 bar, and = 1.30 bar. What is the value of Kp at this temperature?

Give the direction of the reaction if K << 1.

Consider the following reaction and its equilibrium constant: I2(g) ⇌ 2I(g) Kp = 0.209 atm A reaction mixture contains 4.0 atm I2 and 0.5 atm I. Which of the following statements is TRUE concerning this system?

Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows: [N2]eq = 1.5 mol L-1, [H2]eq = 1.1 mol L-1, [NH3]eq = 0.47 mol L-1. N2(g) + 3H2(g) ⇌ 2NH3(g)

Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows: [H2]eq = 0.14 mol L-1, [I2]eq = 0.39 mol L-1, [HI]eq = 1.6 mol L-1. H2(g) + I2(g) ⇌ 2HI(g)

For the following reaction, what is △n required in the conversion of Kc to Kp? 2Na(s) + 2H2O(l) ⇌ 2NaOH(aq) + H2(g)

Express the equilibrium constant for the following reaction: + 6CN-(aq) ⇌ + 6H2O(l)

Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation: At 250° 0. 125 mol L-1 PCl5 is added to the flask. If Kc = 1.80 mol L-1, what are the equilibrium concentrations of each gas?

At a certain temperature, nitogen and hydrogen react to form ammonia: N2(g) + 3 H2(g) ⇌ 2 NH3(g) When initial amounts of N2, H2, and NH3 are mixed, the concentration of NH3 increases. Which statement below is TRUE?

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The decomposition of ammonia is 2NH₃(g) → N₂(g) + 3H₂(g). If K_p is 1.5 × 10³ bar² at 400 °C, what is the partial pressure of ammonia at equilibrium when the partial pressure of N₂(g) is 0. 10 bar and that of H₂(g) is 0.15 bar?

The following reaction is exothermic. Which change will shift the equilibrium to the left? 2SO₂(g) + O₂(g) ⇌ 2SO₃(g)

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) K = 1.7 × 10⁶ SO₃(g) ⇌ 1/2 O₂(g) + SO₂(g) K = ?

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. H₂(g) + Br₂(g) ⇌ 2HBr(g) K = 3.8 × 10⁴ 4HBr(g) ⇌ 2H₂(g) + 2Br₂(g) K = ?

Consider the following reaction at equilibrium. What effect will increasing the temperature have on the system? Fe₃O₄(s) + CO(g) ⇌ 3FeO(s) + CO₂(g) Δ_rH°= +35.9 kJ

Determine the value of K_p for the following reaction if the equilibrium concentrations are as follows: P(CO)_eq = 6.8 × 10^-11 atm, P(O₂)_eq = 1.3 × 10^-3 atm, P(CO₂)_eq = 0.041 atm. 2 CO(g) + O₂(g) ⇌ 2 CO₂(g)

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H₂O(g). C₂H₄(g) + H₂O(g) ⇌ C₂H₅OH(g) K_c = 9.0 × 10³M^-1 [C₂H₄]_eq = 0.015 mol L^-1 [C₂H₅OH]_eq = 1.69 mol L^-1

The reaction below has a K_c value of 61 M^-2. What is the value of K_p for this reaction at 500 K? N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? 2H₂S(g) + 3O₂(g) ⇌ 2H₂O(g) + 2SO₂(g)

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction: (g) + (g) → (g) An equilibrium mixture at 450 K contains = 0.124 bar, = 0.157 bar, and = 1.30 bar. What is the value of K_p at this temperature?

Consider the following reaction and its equilibrium constant: I₂(g) ⇌ 2I(g) K_p = 0.209 atm A reaction mixture contains 4.0 atm I₂ and 0.5 atm I. Which of the following statements is TRUE concerning this system?

Determine the value of K_c for the following reaction if the equilibrium concentrations are as follows: [N₂]_eq = 1.5 mol L^-1, [H₂]_eq = 1.1 mol L^-1, [NH₃]_eq = 0.47 mol L^-1. N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

Determine the value of K_c for the following reaction if the equilibrium concentrations are as follows: [H₂]_eq = 0.14 mol L^-1, [I₂]_eq = 0.39 mol L^-1, [HI]_eq = 1.6 mol L^-1. H₂(g) + I₂(g) ⇌ 2HI(g)

For the following reaction, what is △n required in the conversion of K_c to K_p? 2Na(s) + 2H₂O(l) ⇌ 2NaOH(aq) + H₂(g)

Express the equilibrium constant for the following reaction: + 6CN^-(aq) ⇌ + 6H₂O(l)

Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation: At 250° 0. 125 mol L^-1 PCl₅ is added to the flask. If K_c = 1.80 mol L^-1, what are the equilibrium concentrations of each gas?

At a certain temperature, nitogen and hydrogen react to form ammonia: N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g) When initial amounts of N₂, H₂, and NH₃ are mixed, the concentration of NH₃ increases. Which statement below is TRUE?