Question 1

2.50 mol NOCl was placed in a 2.50 L reaction vessel at 400ºC. After equilibrium was established, it was found that 28% of the NOCl had dissociated according to the equation 2NOCl(g)   ⇌\rightleftharpoons⇌  2NO(g)  + Cl2(g) .Calculate the equilibrium constant, Kc, for the reaction.

Accepted Answer

A)   0.021
B)   0.039
C)   0.169
D)   26
E)   47 F) B) and E)
G) C) and D)

Question 2

Concerning the following reaction at equilibrium: 3Fe(s)  + 4H2O(g)  ⇌ Fe3O4(s)  + 4H2(g) , increasing the concentration of the Fe(s)  would:

Accepted Answer

A)   Shift the equilibrium to the right
B)   Shift the equilibrium to the left
C)   Increase the value of the equilibrium constant, K
D)   Decrease the value of the equilibrium constant, K
E)   Cause no changeF) D) and E)
G) A) and B)

Question 3

Equilibrium constants are known for the following reactions:
S(s) + 3/2O2(g) ⇌ SO3(g) Kc = 9.2 * 1023
SO3(g) ⇌ SO2(g) + 1/2O2(g) Kc = 4.8 * 10- 4
Thus, for the reaction S(s) + O2(g) ⇌ SO2(g), Kc = 4.4 * 1020.

Accepted Answer

A) True 
 B)False

Question 4

For the equilibrium reaction 2SO2(g)  + O2(g)  ⇌ 2SO3(g) ,  Δ\DeltaΔ Hºrxn = -198 kJ/mol. Which one of these factors would cause the equilibrium constant to increase

Accepted Answer

A)   Decrease the temperature.
B)   Add SO2 gas.
C)   Remove O2 gas.
D)   Add a catalyst.
E)   None of these. F) A) and E)
G) C) and E)

Question 5

When the reaction 2H2S(g)  ⇌ 2H2(g)  + S2(g)  is carried out at 1065 ∘\circ∘ C, Kp = 0.012. Starting with pure H2S at 1065 ∘\circ∘ , what must the initial pressure of H2S be if the equilibrated mixture at this temperature is to contain 0.250 atm of H2(g)

Accepted Answer

A)   1.06 atm
B)   1.86 atm
C)   0.94 atm
D)   0.90 atm
E)   1.52 atm F) A) and E)
G) A) and D)

Question 6

A reaction with an equilibrium constant Kc = 1.5 x 1021 would consist of which of the following at equilibrium:

Accepted Answer

A)   approximately equal reactants and products
B)   some reactants and products with reactants slightly favored
C)   some reactants and products with products slightly favored
D)   essentially all reactants
E)   essentially all productsF) A) and E)
G) A) and B)

Question 7

When the following reaction is at equilibrium, which of these relationships is always true
2NOCl(g)   ⇌\rightleftharpoons⇌  2NO(g)  + Cl2(g)

Accepted Answer

A)   [NO] [Cl2] = [NOCl]
B)   [NO]2 [Cl2] = [NOCl]2
C)   [NOCl] = [NO]
D)   2[NO] = [Cl2]
E)   [NO]2 [Cl2] = Kc[NOCl]2 F) A) and C)
G) B) and C)

Question 8

A reaction with an equilibrium constant Kc = 1.5 x 10-25 would consist of which of the following at equilibrium:

Accepted Answer

A)   approximately equal reactants and products
B)   some reactants and products with reactants slightly favored
C)   some reactants and products with products slightly favored
D)   essentially all reactants
E)   essentially all productsF) D) and E)
G) A) and D)

Question 9

Consider the equilibrium C(s) + H2O(g) ⇌ CO(g) + H2(g), $\Delta$H = 2296 J. The concentration of carbon monoxide will increase if the temperature of this system is raised.

Accepted Answer

A) True 
 B)False

Question 10

A solution was prepared such that the initial concentrations of Cu2+(aq)  and CN-(aq)  were 0.0120 M and 0.0400 M, respectively. These ions react according to the following chemical equation:
 Cu2+(aq) +4CN−(aq) ⇌Cd(CN) 42−(aq) \mathrm{Cu}^{2+}(a q) +4 \mathrm{CN}^{-}(a q)  ightleftharpoons \mathrm{Cd}(\mathrm{CN}) _{4}^{2-}(a q) Cu2+(aq) +4CN−(aq) ⇌Cd(CN) 42−​(aq)

Kc=1.0×1025\mathrm{K}_{\mathrm{c}}=1.0 	imes 10^{25}Kc​=1.0×1025   
 What will be the concentration of CN-(aq)  at equilibrium

Accepted Answer

A)   2.4 * 10-7 M
B)   4.4 * 10-7 M
C)   6.4 * 10-7 M
D)   8.4 * 10-7 M
E)   None of the above F) B) and C)
G) A) and D)

Question 11

4.21 moles of S2Cl4 are introduced into a 2.0 L vessel.S2Cl4(g)  ⇌ 2SCl2(g)  At equilibrium, 1.25 moles of S2Cl4 are found to remain in the container. Calculate Kc for this reaction.

Accepted Answer

A)   Kc = 10.0
B)   Kc = 12.0
C)   Kc = 14.0
D)   Kc = 16.0
E)   None of the aboveF) A) and B)
G) A) and E)

Question 12

Consider the two gaseous equilibria:  SO2(g) + 1/2O2( g) ⇋SO3(g) K12SO3(g) ⇋SO2(g) +O2(g) K2\begin{array}{ll}\mathrm{SO}_{2}(\mathrm{g}) +~^1/_2 \mathrm{O}_{2}(\mathrm{~g})  \leftrightharpoons \mathrm{SO}_{3}(\mathrm{g})  & \mathrm{K}_{1} \2 \mathrm{SO}_{3}(\mathrm{g})  \leftrightharpoons \mathrm{SO}_{2}(\mathrm{g}) +\mathrm{O}_{2}(\mathrm{g})  & \mathrm{K}_{2}\end{array}SO2​(g) + 1/2​O2​( g) ⇋SO3​(g) 2SO3​(g) ⇋SO2​(g) +O2​(g) ​K1​K2​​  The values of the equilibrium constants K1 and K2 are related by

Accepted Answer

A)   K2 = K12
B)   K22 = K1
C)  K2 = 1/K12
D)   K2 = 1/K1
E)   none of these. F) None of the above
G) All of the above

Question 13

Consider this reaction at equilibrium at a total pressure P1: 2SO2(g)  + O2(g)  ⇌ 2SO3(g) 
Suppose the volume of this system is compressed to one-half its initial volume and then equilibrium is reestablished. The new equilibrium total pressure will be

Accepted Answer

A)   twice P1.
B)   three times P1.
C)   3.5 P1.
D)   less than twice P1.
E)   unchanged.F) A) and B)
G) B) and E)

Question 14

Consider the equilibrium C(s) + H2O(g) ⇌ CO(g) + H2(g), $\Delta$H = 2296 J. The concentration of carbon will not change if gaseous water is added to the system.

Accepted Answer

A) True 
 B)False

Question 15

Consider the reaction, N2(g)  + 3H2(g)  ⇌ 2NH3(g) . Kc = 8.1 x 10-3 at 900 K.What is the value of Kc for NH3(g)  ⇌ (1/2) N2(g)  + 3/2H2(g)

Accepted Answer

A)   17
B)   15
C)   13
D)   11
E)   None of the aboveF) None of the above
G) B) and E)

Question 16

Consider the following equilibria: 
2SO3(g)  ⇌ 2SO2(g)  + O2(g)  Kc = 2.3 * 10-7
2NO3(g)  ⇌ 2NO2(g)  + O2(g)  Kc = 1.4 * 10-3
Calculate the equilibrium constant for the reaction
SO2(g)  + NO3(g)  ⇌ SO3(g)  + NO2(g)

Accepted Answer

A)   78
B)   1.3 * 10-2
C)   1.6 * 10-4
D)   3.2 * 10-10
E)   6.1 * 103F) C) and D)
G) C) and E)

Question 17

In which of these gas-phase equilibria is the yield of products increased by increasing the total pressure on the reaction mixture

Accepted Answer

A)   CO(g)  + H2O(g)  ⇌ CO2(g)  + H2(g) 
B)   2NO(g)  + Cl2(g)  ⇌ 2NOCl(g) 
C)   2SO3(g)  ⇌ 2SO2(g)  + O2(g) 
D)   PCl5(g)  ⇌ PCl3(g)  + Cl2(g) 
E)   H2(g)  + I2(g)  ⇌ 2HI(g) F) A) and B)
G) A) and E)

Question 18

Consider the following equilibrium:
4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(g) + 1531 kJ
The concentrations of the reactants will increase when the temperature is increased.

Accepted Answer

A) True 
 B)False

Question 19

Given the following data for the reaction: A(g) + 2B(s) ⇌ AB2(g) $\begin{array}{|l|l|}
\hline \text { Temperature }(\mathrm{K}) & \mathrm{K}_{\mathrm{c}} \
\hline 300 & 1.2 \times 10^{-2} \
\hline 600 & 12 \
\hline 900 & 2.2 \times 10^{5} \
\hline
\end{array}$ This data represents an endothermic reaction.

Accepted Answer

A) True 
 B)False

Question 20

4.2 mol of oxygen and 4.0 mol of NO are introduced to an evacuated 0.50 L reaction vessel. At a specific temperature, the equilibrium 2NO(g)  + O2(g)  ⇌ 2NO2(g)  is reached when [NO] = 1.6 M. Calculate Kc for the reaction at this temperature.

Accepted Answer

A)   Kc = 3.1
B)   Kc = 3.3
C)   Kc = 3.5
D)   Kc = 3.7
E)   None of the aboveF) A) and D)
G) A) and C)

Exam 14: Chemical Equilibrium

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

Correct Answer
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2.50 mol NOCl was placed in a 2.50 L reaction vessel at 400ºC. After equilibrium was established, it was found that 28% of the NOCl had dissociated according to the equation 2NOCl(g) $\rightleftharpoons$ 2NO(g) + Cl₂(g) .Calculate the equilibrium constant, K_c, for the reaction.

Correct Answer
verified

Consider the equilibrium C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$ H = 2296 J. The concentration of carbon monoxide will increase if the temperature of this system is raised.

Correct Answer
verified

In which of these gas-phase equilibria is the yield of products increased by increasing the total pressure on the reaction mixture

Correct Answer
verified

When the following reaction is at equilibrium, which of these relationships is always true 2NOCl(g) $\rightleftharpoons$ 2NO(g) + Cl₂(g)

Correct Answer
verified

For the equilibrium reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) , $\Delta$ Hº_rxn = -198 kJ/mol. Which one of these factors would cause the equilibrium constant to increase

Correct Answer
verified

Consider this reaction at equilibrium at a total pressure P₁: 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) Suppose the volume of this system is compressed to one-half its initial volume and then equilibrium is reestablished. The new equilibrium total pressure will be

Correct Answer
verified

Consider the reaction, N₂(g) + 3H₂(g) ⇌ 2NH₃(g) . K_c = 8.1 x 10^-3 at 900 K.What is the value of K_c for NH₃(g) ⇌ (1/2) N₂(g) + 3/2H₂(g)

Correct Answer
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A reaction with an equilibrium constant K_c = 1.5 x 10²¹ would consist of which of the following at equilibrium:

Correct Answer
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4.2 mol of oxygen and 4.0 mol of NO are introduced to an evacuated 0.50 L reaction vessel. At a specific temperature, the equilibrium 2NO(g) + O₂(g) ⇌ 2NO₂(g) is reached when [NO] = 1.6 M. Calculate K_c for the reaction at this temperature.

Correct Answer
verified

Consider the following equilibria: 2SO₃(g) ⇌ 2SO₂(g) + O₂(g) K_c = 2.3 * 10^-7 2NO₃(g) ⇌ 2NO₂(g) + O₂(g) K_c = 1.4 * 10^-3 Calculate the equilibrium constant for the reaction SO₂(g) + NO₃(g) ⇌ SO₃(g) + NO₂(g)

Correct Answer
verified

Concerning the following reaction at equilibrium: 3Fe(s) + 4H₂O(g) ⇌ Fe₃O₄(s) + 4H₂(g) , increasing the concentration of the Fe(s) would:

Correct Answer
verified

Correct Answer
verified

4.21 moles of S₂Cl₄ are introduced into a 2.0 L vessel.S₂Cl₄(g) ⇌ 2SCl₂(g) At equilibrium, 1.25 moles of S₂Cl₄ are found to remain in the container. Calculate K_c for this reaction.

Correct Answer
verified

Consider the equilibrium C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$ H = 2296 J. The concentration of carbon will not change if gaseous water is added to the system.

Correct Answer
verified

Correct Answer
verified

Equilibrium constants are known for the following reactions: S(s) + ³/₂O₂(g) ⇌ SO₃(g) K_c = 9.2 * 10²³ SO₃(g) ⇌ SO₂(g) + ¹/₂O₂(g) K_c = 4.8 * 10^{- 4} Thus, for the reaction S(s) + O₂(g) ⇌ SO₂(g), K_c = 4.4 * 10²⁰.

Correct Answer
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When the reaction 2H₂S(g) ⇌ 2H₂(g) + S₂(g) is carried out at 1065^$\circ$C, K_p = 0.012. Starting with pure H₂S at 1065^$\circ$, what must the initial pressure of H₂S be if the equilibrated mixture at this temperature is to contain 0.250 atm of H₂(g)

Correct Answer
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Correct Answer
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A reaction with an equilibrium constant K_c = 1.5 x 10^-25 would consist of which of the following at equilibrium:

Correct Answer
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Exam 14: Chemical Equilibrium

Consider the following equilibrium: 4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

Correct AnswerverifiedShow Answer

2.50 mol NOCl was placed in a 2.50 L reaction vessel at 400ºC. After equilibrium was established, it was found that 28% of the NOCl had dissociated according to the equation 2NOCl(g) ⇌\rightleftharpoons⇌ 2NO(g) + Cl2(g) .Calculate the equilibrium constant, Kc, for the reaction.

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Consider the equilibrium C(s) + H2O(g) ⇌ CO(g) + H2(g), Δ\DeltaΔ H = 2296 J. The concentration of carbon monoxide will increase if the temperature of this system is raised.

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In which of these gas-phase equilibria is the yield of products increased by increasing the total pressure on the reaction mixture

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When the following reaction is at equilibrium, which of these relationships is always true 2NOCl(g) ⇌\rightleftharpoons⇌ 2NO(g) + Cl2(g)

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For the equilibrium reaction 2SO2(g) + O2(g) ⇌ 2SO3(g) , Δ\DeltaΔ Hºrxn = -198 kJ/mol. Which one of these factors would cause the equilibrium constant to increase

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Consider this reaction at equilibrium at a total pressure P1: 2SO2(g) + O2(g) ⇌ 2SO3(g) Suppose the volume of this system is compressed to one-half its initial volume and then equilibrium is reestablished. The new equilibrium total pressure will be

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Consider the reaction, N2(g) + 3H2(g) ⇌ 2NH3(g) . Kc = 8.1 x 10-3 at 900 K.What is the value of Kc for NH3(g) ⇌ (1/2) N2(g) + 3/2H2(g)

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A reaction with an equilibrium constant Kc = 1.5 x 1021 would consist of which of the following at equilibrium:

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4.2 mol of oxygen and 4.0 mol of NO are introduced to an evacuated 0.50 L reaction vessel. At a specific temperature, the equilibrium 2NO(g) + O2(g) ⇌ 2NO2(g) is reached when [NO] = 1.6 M. Calculate Kc for the reaction at this temperature.

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Consider the following equilibria: 2SO3(g) ⇌ 2SO2(g) + O2(g) Kc = 2.3 * 10-7 2NO3(g) ⇌ 2NO2(g) + O2(g) Kc = 1.4 * 10-3 Calculate the equilibrium constant for the reaction SO2(g) + NO3(g) ⇌ SO3(g) + NO2(g)

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Concerning the following reaction at equilibrium: 3Fe(s) + 4H2O(g) ⇌ Fe3O4(s) + 4H2(g) , increasing the concentration of the Fe(s) would:

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4.21 moles of S2Cl4 are introduced into a 2.0 L vessel.S2Cl4(g) ⇌ 2SCl2(g) At equilibrium, 1.25 moles of S2Cl4 are found to remain in the container. Calculate Kc for this reaction.

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Consider the equilibrium C(s) + H2O(g) ⇌ CO(g) + H2(g), Δ\DeltaΔ H = 2296 J. The concentration of carbon will not change if gaseous water is added to the system.

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Equilibrium constants are known for the following reactions: S(s) + 3/2O2(g) ⇌ SO3(g) Kc = 9.2 * 1023 SO3(g) ⇌ SO2(g) + 1/2O2(g) Kc = 4.8 * 10- 4 Thus, for the reaction S(s) + O2(g) ⇌ SO2(g), Kc = 4.4 * 1020.

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When the reaction 2H2S(g) ⇌ 2H2(g) + S2(g) is carried out at 1065 ∘\circ∘ C, Kp = 0.012. Starting with pure H2S at 1065 ∘\circ∘ , what must the initial pressure of H2S be if the equilibrated mixture at this temperature is to contain 0.250 atm of H2(g)

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A reaction with an equilibrium constant Kc = 1.5 x 10-25 would consist of which of the following at equilibrium:

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Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

Correct Answer
verified

2.50 mol NOCl was placed in a 2.50 L reaction vessel at 400ºC. After equilibrium was established, it was found that 28% of the NOCl had dissociated according to the equation 2NOCl(g) $\rightleftharpoons$ 2NO(g) + Cl₂(g) .Calculate the equilibrium constant, K_c, for the reaction.

Correct Answer
verified

Consider the equilibrium C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$ H = 2296 J. The concentration of carbon monoxide will increase if the temperature of this system is raised.

Correct Answer
verified

Correct Answer
verified

When the following reaction is at equilibrium, which of these relationships is always true 2NOCl(g) $\rightleftharpoons$ 2NO(g) + Cl₂(g)

Correct Answer
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For the equilibrium reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) , $\Delta$ Hº_rxn = -198 kJ/mol. Which one of these factors would cause the equilibrium constant to increase

Correct Answer
verified

Consider this reaction at equilibrium at a total pressure P₁: 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) Suppose the volume of this system is compressed to one-half its initial volume and then equilibrium is reestablished. The new equilibrium total pressure will be

Correct Answer
verified

Consider the reaction, N₂(g) + 3H₂(g) ⇌ 2NH₃(g) . K_c = 8.1 x 10^-3 at 900 K.What is the value of K_c for NH₃(g) ⇌ (1/2) N₂(g) + 3/2H₂(g)

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A reaction with an equilibrium constant K_c = 1.5 x 10²¹ would consist of which of the following at equilibrium:

Correct Answer
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4.2 mol of oxygen and 4.0 mol of NO are introduced to an evacuated 0.50 L reaction vessel. At a specific temperature, the equilibrium 2NO(g) + O₂(g) ⇌ 2NO₂(g) is reached when [NO] = 1.6 M. Calculate K_c for the reaction at this temperature.

Correct Answer
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Consider the following equilibria: 2SO₃(g) ⇌ 2SO₂(g) + O₂(g) K_c = 2.3 * 10^-7 2NO₃(g) ⇌ 2NO₂(g) + O₂(g) K_c = 1.4 * 10^-3 Calculate the equilibrium constant for the reaction SO₂(g) + NO₃(g) ⇌ SO₃(g) + NO₂(g)

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Concerning the following reaction at equilibrium: 3Fe(s) + 4H₂O(g) ⇌ Fe₃O₄(s) + 4H₂(g) , increasing the concentration of the Fe(s) would:

Correct Answer
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Correct Answer
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4.21 moles of S₂Cl₄ are introduced into a 2.0 L vessel.S₂Cl₄(g) ⇌ 2SCl₂(g) At equilibrium, 1.25 moles of S₂Cl₄ are found to remain in the container. Calculate K_c for this reaction.

Correct Answer
verified

Consider the equilibrium C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$ H = 2296 J. The concentration of carbon will not change if gaseous water is added to the system.

Correct Answer
verified

Correct Answer
verified

Equilibrium constants are known for the following reactions: S(s) + ³/₂O₂(g) ⇌ SO₃(g) K_c = 9.2 * 10²³ SO₃(g) ⇌ SO₂(g) + ¹/₂O₂(g) K_c = 4.8 * 10^{- 4} Thus, for the reaction S(s) + O₂(g) ⇌ SO₂(g), K_c = 4.4 * 10²⁰.

Correct Answer
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When the reaction 2H₂S(g) ⇌ 2H₂(g) + S₂(g) is carried out at 1065^$\circ$C, K_p = 0.012. Starting with pure H₂S at 1065^$\circ$, what must the initial pressure of H₂S be if the equilibrated mixture at this temperature is to contain 0.250 atm of H₂(g)

Correct Answer
verified

Correct Answer
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A reaction with an equilibrium constant K_c = 1.5 x 10^-25 would consist of which of the following at equilibrium:

Correct Answer
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