Question 1

Which of the following statements is TRUE?

Accepted Answer

A) If Q  K, it means the reverse reaction will proceed to form more reactants. 
C) If Q = K, it means the reaction is not at equilibrium. 
D) Because the equilibrium is always dynamic, Q can never be equal to K. 
E) If Q < K, the reaction proceeding to the left is much faster than the reaction proceeding to the right. 
A) If Q  K, it means the reverse reaction will proceed to form more reactants. 
C) If Q = K, it means the reaction is not at equilibrium. 
D) Because the equilibrium is always dynamic, Q can never be equal to K. 
E) If Q < K, the reaction proceeding to the left is much faster than the reaction proceeding to the right.

Question 2

Express the equilibrium constant for the following reaction: KClO3(s)⇌ KClO(s)+ O2(g)

Accepted Answer

A) Kc =   
B) Kc = [O2]-1 
C) Kc =   
D) Kc =   
E) Kc = [O2] 
A) Kc =   
B) Kc = [O2]-1 
C) Kc =   
D) Kc =   
E) Kc = [O2]

Question 3

Consider the following reaction: Xe(g)+ 2F2(g)⇌ XeF4(g)
A reaction mixture initially contains 2.24 bar Xe and 4.27 bar F2. If the equilibrium pressure of Xe is 0.34 bar, find the equilibrium constant (Kp)for the reaction.

Accepted Answer

A) 25 bar-2 
B) 0.12 bar-2 
C) 0.99 bar-2 
D) 8.3 bar-2 
E) 0.040 bar-2 
A) 25 bar-2 
B) 0.12 bar-2 
C) 0.99 bar-2 
D) 8.3 bar-2 
E) 0.040 bar-2

Question 4

Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? CuS(s)+ O2(g)⇌ Cu(s)+ SO2(g)

Accepted Answer

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

Question 5

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 6

Match the following.

-K ≈ 1

Accepted Answer

A) reaction will favour formation of reactants 
B) reaction has a larger amount of products than reactants 
C) reaction favours formation of more products 
D) reverse reaction is favoured 
E) reaction does not strongly favour reactants or products
F)reaction is at equilibrium 
A) reaction will favour formation of reactants 
B) reaction has a larger amount of products than reactants 
C) reaction favours formation of more products 
D) reverse reaction is favoured 
E) reaction does not strongly favour reactants or products
F)reaction is at equilibrium

Question 7

Consider the following reaction: CuS(s)+ O2(g)⇌ Cu(s)+ SO2(g)
A reaction mixture initially contains 2.9 mol L-1 O2. Determine the equilibrium concentration of O2 if Kc for the reaction at this temperature is 1.5.

Accepted Answer

A) 1.9 mol L-1 
B) 1.7 mol L-1 
C) 2.2 mol L-1 
D) 1.2 mol L-1 
E) 0.59 mol L-1 
A) 1.9 mol L-1 
B) 1.7 mol L-1 
C) 2.2 mol L-1 
D) 1.2 mol L-1 
E) 0.59 mol L-1

Question 8

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium pressure of CO. CO(g)+ 2H2(g)⇌ CH3OH(l)Kp = 2.25 × 104 bar-3
P(H2)eq = 0.52 bar

Accepted Answer

A) 8.3 × 104 bar 
B) 1.2 × 10-5 bar 
C) 6.25 × 10-3 bar 
D) 8.5 × 10-5 bar 
E) 1.6 × 10-4 bar 
A) 8.3 × 104 bar 
B) 1.2 × 10-5 bar 
C) 6.25 × 10-3 bar 
D) 8.5 × 10-5 bar 
E) 1.6 × 10-4 bar

Question 9

An equilibrium mixture of CO, O2, and CO2 at a certain temperature contains 0.0010 mol L-1 CO2 and 0.0015 mol L-1 O2. At this temperature, Kc equals 1.4 × 102 L mol-1 for the reaction: 2CO(g)+ O2(g)⇌ 2CO2(g)
What is the equilibrium concentration of CO?

Accepted Answer

A) 4.8 × 10-6 mol L-1 
B) 8.5 × 10-3 mol L-1 
C) 9.3 × 10-2 mol L-1 
D) 3.1 × 10-1 mol L-1 
A) 4.8 × 10-6 mol L-1 
B) 8.5 × 10-3 mol L-1 
C) 9.3 × 10-2 mol L-1 
D) 3.1 × 10-1 mol L-1

Question 10

Consider the following reaction at equilibrium. What effect will removing NO2 have on the system? SO2(g)+ NO2(g)⇌ SO3(g)+ NO(g)

Accepted Answer

A) The reaction will shift in the direction of products. 
B) The reaction will shift to decrease the pressure. 
C) No change will occur since NO2 is not included in the equilibrium expression. 
D) The reaction will shift in the direction of reactants. 
E) The equilibrium constant will decrease. 
A) The reaction will shift in the direction of products. 
B) The reaction will shift to decrease the pressure. 
C) No change will occur since NO2 is not included in the equilibrium expression. 
D) The reaction will shift in the direction of reactants. 
E) The equilibrium constant will decrease.

Question 11

Express the equilibrium constant for the following reaction: P(g)+ 3/2 Cl2(g)⇌ PCl3(g)

Accepted Answer

A) KP =   
B) KP =   
C) KP =   
D) KP =   
E) Kp =   
A) KP =   
B) KP =   
C) KP =   
D) KP =   
E) Kp =

Question 12

Match the following.

-Q = K

Accepted Answer

A) reaction will favour formation of reactants 
B) reaction has a larger amount of products than reactants 
C) reaction favours formation of more products 
D) reverse reaction is favoured 
E) reaction does not strongly favour reactants or products
F)reaction is at equilibrium 
A) reaction will favour formation of reactants 
B) reaction has a larger amount of products than reactants 
C) reaction favours formation of more products 
D) reverse reaction is favoured 
E) reaction does not strongly favour reactants or products
F)reaction is at equilibrium

Question 13

The equilibrium constant, Kp, equals 3.40 at 25 °C for the isomerization reaction: cis-2-butene ⇌ trans-2-butene
If a flask initially contains 5.00 bar of each gas, in what direction will the system shift to reach equilibrium?

Accepted Answer

A) It will shift left. 
B) It will shift right. 
C) The system is already at equilibrium. 
D) The system is not at equilibrium and will remain in an unequilibrated state. 
A) It will shift left. 
B) It will shift right. 
C) The system is already at equilibrium. 
D) The system is not at equilibrium and will remain in an unequilibrated state.

Question 14

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 15

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. N2O4(g)⇌ 2NO2(g)K = 1.46
3N2O4(g)⇌ 6NO2(g)K = ?

Accepted Answer

A) 2.13 
B) 0.685 
C) 3.11 
D) 1.46 
E) 1.13 
A) 2.13 
B) 0.685 
C) 3.11 
D) 1.46 
E) 1.13

Question 16

Express the equilibrium constant for the following reaction: PCl5(g)⇌ PCl3(g)+ Cl2(g)

Accepted Answer

A) KP =   
B) KP =   
C) KP =   
D) KP =   
E) KP =   
A) KP =   
B) KP =   
C) KP =   
D) KP =   
E) KP =

Question 17

Consider the following reaction at equilibrium. What effect will adding CO2 have on the system? CO2(g)+ C(graphite)⇌ 2CO(g)

Accepted Answer

A) No effect will be observed since CO2 is not included in the equilibrium expression. 
B) The equilibrium constant will decrease. 
C) The reaction will shift in the direction of reactants. 
D) The equilibrium constant will increase. 
E) The reaction will shift in the direction of products. 
A) No effect will be observed since CO2 is not included in the equilibrium expression. 
B) The equilibrium constant will decrease. 
C) The reaction will shift in the direction of reactants. 
D) The equilibrium constant will increase. 
E) The reaction will shift in the direction of products.

Question 18

Express the equilibrium constant for the following reaction: 2P(g)+ 3Cl2(g)⇌ 2PCl3(g)

Accepted Answer

A) KP =   
B) KP =   
C) KP =   
D) KP =   
E) KP =   
A) KP =   
B) KP =   
C) KP =   
D) KP =   
E) KP =

Question 19

In a reaction mixture containing only reactants, what is the value of Q?

Accepted Answer

A) -1 
B) 1 
C) ∞ 
D) 0 
E) Q = K 
A) -1 
B) 1 
C) ∞ 
D) 0 
E) Q = K

Question 20

Consider the following reaction: CO2(g)+ C(graphite)⇌ 2CO(g)
A reaction mixture initially contains 0.56 bar CO2 and 0.32 bar CO. Determine the equilibrium pressure of CO if Kp for the reaction at this temperature is 2.25 bar.

Accepted Answer

A) 0.83 bar 
B) 0.31 bar 
C) 0.26 bar 
D) 0.58 bar 
E) 0.42 bar 
A) 0.83 bar 
B) 0.31 bar 
C) 0.26 bar 
D) 0.58 bar 
E) 0.42 bar

Exam 14: Chemical Equilibrium

Which of the following statements is TRUE?

Express the equilibrium constant for the following reaction: KClO3(s)⇌ KClO(s)+ O2(g)

Consider the following reaction: Xe(g)+ 2F2(g)⇌ XeF4(g) A reaction mixture initially contains 2.24 bar Xe and 4.27 bar F2. If the equilibrium pressure of Xe is 0.34 bar, find the equilibrium constant (Kp)for the reaction.

Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? CuS(s)+ O2(g)⇌ Cu(s)+ SO2(g)

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

Match the following. -K ≈ 1

Consider the following reaction: CuS(s)+ O2(g)⇌ Cu(s)+ SO2(g) A reaction mixture initially contains 2.9 mol L-1 O2. Determine the equilibrium concentration of O2 if Kc for the reaction at this temperature is 1.5.

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium pressure of CO. CO(g)+ 2H2(g)⇌ CH3OH(l)Kp = 2.25 × 104 bar-3 P(H2)eq = 0.52 bar

An equilibrium mixture of CO, O2, and CO2 at a certain temperature contains 0.0010 mol L-1 CO2 and 0.0015 mol L-1 O2. At this temperature, Kc equals 1.4 × 102 L mol-1 for the reaction: 2CO(g)+ O2(g)⇌ 2CO2(g) What is the equilibrium concentration of CO?

Consider the following reaction at equilibrium. What effect will removing NO2 have on the system? SO2(g)+ NO2(g)⇌ SO3(g)+ NO(g)

Express the equilibrium constant for the following reaction: P(g)+ 3/2 Cl2(g)⇌ PCl3(g)

Match the following. -Q = K

The equilibrium constant, Kp, equals 3.40 at 25 °C for the isomerization reaction: cis-2-butene ⇌ trans-2-butene If a flask initially contains 5.00 bar of each gas, in what direction will the system shift to reach equilibrium?

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)

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. N2O4(g)⇌ 2NO2(g)K = 1.46 3N2O4(g)⇌ 6NO2(g)K = ?

Express the equilibrium constant for the following reaction: PCl5(g)⇌ PCl3(g)+ Cl2(g)

Consider the following reaction at equilibrium. What effect will adding CO2 have on the system? CO2(g)+ C(graphite)⇌ 2CO(g)

Express the equilibrium constant for the following reaction: 2P(g)+ 3Cl2(g)⇌ 2PCl3(g)

In a reaction mixture containing only reactants, what is the value of Q?

Consider the following reaction: CO2(g)+ C(graphite)⇌ 2CO(g) A reaction mixture initially contains 0.56 bar CO2 and 0.32 bar CO. Determine the equilibrium pressure of CO if Kp for the reaction at this temperature is 2.25 bar.

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Filters

Express the equilibrium constant for the following reaction: KClO₃(s)⇌ KClO(s)+ O₂(g)

Consider the following reaction: Xe(g)+ 2F₂(g)⇌ XeF₄(g) A reaction mixture initially contains 2.24 bar Xe and 4.27 bar F₂. If the equilibrium pressure of Xe is 0.34 bar, find the equilibrium constant (K_p)for the reaction.

Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? CuS(s)+ O₂(g)⇌ Cu(s)+ SO₂(g)

Consider the following reaction: CuS(s)+ O₂(g)⇌ Cu(s)+ SO₂(g) A reaction mixture initially contains 2.9 mol L^-1 O₂. Determine the equilibrium concentration of O₂ if K_c for the reaction at this temperature is 1.5.

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium pressure of CO. CO(g)+ 2H₂(g)⇌ CH₃OH(l)K_p = 2.25 × 10⁴bar^-3 P(H₂)_eq = 0.52 bar

An equilibrium mixture of CO, O₂, and CO₂ at a certain temperature contains 0.0010 mol L^-1 CO₂ and 0.0015 mol L^-1 O₂. At this temperature, K_c equals 1.4 × 10² L mol^-1 for the reaction: 2CO(g)+ O₂(g)⇌ 2CO₂(g) What is the equilibrium concentration of CO?

Consider the following reaction at equilibrium. What effect will removing NO₂ have on the system? SO₂(g)+ NO₂(g)⇌ SO₃(g)+ NO(g)

Express the equilibrium constant for the following reaction: P(g)+ 3/2 Cl₂(g)⇌ PCl₃(g)

The equilibrium constant, K_p, equals 3.40 at 25 °C for the isomerization reaction: cis-2-butene ⇌ trans-2-butene If a flask initially contains 5.00 bar of each gas, in what direction will the system shift to reach equilibrium?

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)

The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. N₂O₄(g)⇌ 2NO₂(g)K = 1.46 3N₂O₄(g)⇌ 6NO₂(g)K = ?

Express the equilibrium constant for the following reaction: PCl₅(g)⇌ PCl₃(g)+ Cl₂(g)

Consider the following reaction at equilibrium. What effect will adding CO₂ have on the system? CO₂(g)+ C(graphite)⇌ 2CO(g)

Express the equilibrium constant for the following reaction: 2P(g)+ 3Cl₂(g)⇌ 2PCl₃(g)

Consider the following reaction: CO₂(g)+ C(graphite)⇌ 2CO(g) A reaction mixture initially contains 0.56 bar CO₂ and 0.32 bar CO. Determine the equilibrium pressure of CO if K_p for the reaction at this temperature is 2.25 bar.