Question 1

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? CO2 (s) + H2O (l)   H+ (aq) + HCO3- (aq)

Accepted Answer

A) [H+][HCO3-] / [CO2] 
B) [CO2] / [H+][HCO3-] 
C) [H+][HCO3-] / [CO2][H2O] 
D) [CO2][H2O] / [H+][HCO3-] 
E) [H+][HCO3-] 
A) [H+][HCO3-] / [CO2] 
B) [CO2] / [H+][HCO3-] 
C) [H+][HCO3-] / [CO2][H2O] 
D) [CO2][H2O] / [H+][HCO3-] 
E) [H+][HCO3-]

Question 2

Given the following reaction at equilibrium, if Kc = 5.84 x 105 at 230.0 °C, Kp = ________. 2NO (g) + O2 (g)   2NO2 (g)

Accepted Answer

A) 3.67 × 10-2 
B) 1.41 × 104 
C) 6.44 × 105 
D) 2.40 × 106 
E) 2.41 × 107 
A) 3.67 × 10-2 
B) 1.41 × 104 
C) 6.44 × 105 
D) 2.40 × 106 
E) 2.41 × 107

Question 3

The Keq for the equilibrium below is 0.112 at 700.0 °C. SO2 (g) +   O2 (g)   SO3 (g)
What is the value of Keq at this temperature for the following reaction?
2SO3 (g)   2SO2 (g) + O2 (g)

Accepted Answer

A) 79.7 
B) 2.99 
C) 17.86 
D) 4.46 
E) 8.93 
A) 79.7 
B) 2.99 
C) 17.86 
D) 4.46 
E) 8.93

Question 4

Pure ________ and pure ________ are excluded from equilibrium-constant expressions.

Accepted Answer

The answer of Pure ________ and pure ________ are excluded...

Question 5

Which of the following statements is true?

Accepted Answer

A) Q does not change with temperature. 
B) Keq does not change with temperature, whereas Q is temperature dependent. 
C) K does not depend on the concentrations or partial pressures of reaction components. 
D) Q does not depend on the concentrations or partial pressures of reaction components. 
E) Q is the same as Keq when a reaction is at equilibrium. 
A) Q does not change with temperature. 
B) Keq does not change with temperature, whereas Q is temperature dependent. 
C) K does not depend on the concentrations or partial pressures of reaction components. 
D) Q does not depend on the concentrations or partial pressures of reaction components. 
E) Q is the same as Keq when a reaction is at equilibrium.

Question 6

The equilibrium constant for the gas phase reaction 2SO2 (g) + O2 (g)   2SO3 (g)
Is Keq = 2.80 × 102 at 999 K. At equilibrium, ________.

Accepted Answer

A) products predominate 
B) reactants predominate 
C) roughly equal amounts of products and reactants are present 
D) only products are present 
E) only reactants are present 
A) products predominate 
B) reactants predominate 
C) roughly equal amounts of products and reactants are present 
D) only products are present 
E) only reactants are present

Question 7

The equilibrium constant for the gas phase reaction N2 (g) + 3H2 (g)   2NH3 (g)
Is Keq = 4.34 × 10-3 at 300 °C. At equilibrium, ________.

Accepted Answer

A) products predominate 
B) reactants predominate 
C) roughly equal amounts of products and reactants are present 
D) only products are present 
E) only reactants are present 
A) products predominate 
B) reactants predominate 
C) roughly equal amounts of products and reactants are present 
D) only products are present 
E) only reactants are present

Question 8

Consider the following reaction at equilibrium: 2SO2 (g) + O2 (g)   2SO3 (g)ΔH° = -99 kJ
Le Châtelier's principle predicts that a(n)increase in temperature will result in ________.

Accepted Answer

A) an increase in the partial pressure of O2 
B) a decrease in the partial pressure of O2 
C) a decrease in the partial pressure of SO2 
D) a(n)increase in Keq 
E) no changes in equilibrium partial pressures 
A) an increase in the partial pressure of O2 
B) a decrease in the partial pressure of O2 
C) a decrease in the partial pressure of SO2 
D) a(n)increase in Keq 
E) no changes in equilibrium partial pressures

Question 9

The Keq for the equilibrium below is 7.52 × 10-2 at 480.0 °C. 2Cl2 (g) + 2H2O (g)   4HCl (g) + O2 (g)
What is the value of Keq at this temperature for the following reaction?
2HCl (g) +   O2 (g)   Cl2 (g) + H2O (g)

Accepted Answer

A) 13.3 
B) 3.65 
C) -0.0376 
D) 5.66 × 10-3 
E) 0.274 
A) 13.3 
B) 3.65 
C) -0.0376 
D) 5.66 × 10-3 
E) 0.274

Question 10

The number obtained by substituting starting reactant and product concentrations into an equilibrium-constant expression is known as the ________.

Accepted Answer

The answer of The number obtained by substituting starting reactant...

Question 11

Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g)   2 NO2 (g)
A 1.00-L flask is charged with   ofN2O4. At equilibrium at 373 K, 0.0055 mol of N2O4 remains. Keq for this reaction is ________.

Accepted Answer

A) 2.2 × 10-4 
B) 13 
C) 0.22 
D) 0.022 
E) 0.87 
A) 2.2 × 10-4 
B) 13 
C) 0.22 
D) 0.022 
E) 0.87

Question 12

Given the following reaction at equilibrium at 450.0 °C: CaCO3 (s)   CaO (s) + CO2 (g)
If pCO2 = 0.0155 atm, Kc = ________.

Accepted Answer

A) 155 
B) 0.0821 
C) 0.920 
D) 2.61 × 10-4 
E) 9.20 
A) 155 
B) 0.0821 
C) 0.920 
D) 2.61 × 10-4 
E) 9.20

Question 13

Consider the following reaction at equilibrium: 2NH3 (g)   N2 (g) + 3H2 (g)ΔH° = +92.4 kJ
Le Châtelier's principle predicts that removing N2 (g)to the system at equilibrium will result in ________.

Accepted Answer

A) an increase in the concentration of H2 
B) a decrease in the concentration of H2 
C) removal of all of the H2 
D) a lower partial pressure of H2 
E) an increase in the value of the equilibrium constant 
A) an increase in the concentration of H2 
B) a decrease in the concentration of H2 
C) removal of all of the H2 
D) a lower partial pressure of H2 
E) an increase in the value of the equilibrium constant

Question 14

The Keq for the equilibrium below is 0.112 at 700.0 °C. SO2 (g) +   O2 (g)   SO3 (g)
What is the value of Keq at this temperature for the following reaction?
SO3 (g)   SO2 (g) +   O2 (g)

Accepted Answer

A) 0.224 
B) 0.0125 
C) 0.112 
D) 8.93 
E) -0.112 
A) 0.224 
B) 0.0125 
C) 0.112 
D) 8.93 
E) -0.112

Question 15

The value of Keq for the equilibrium N2 (g) + O2 (g)   2 NO (g)
Is 4.2 × 10-31 at 27 °C. What is the value of Keq for the equilibrium below?
4 NO (g)   2 N2 (g) + 2 O2 (g)

Accepted Answer

A) 5.7 × 1060 
B) 8.4 × 10-31 
C) 4.2 × 1031 
D) 8.4 × 1031 
E) none of the above 
A) 5.7 × 1060 
B) 8.4 × 10-31 
C) 4.2 × 1031 
D) 8.4 × 1031 
E) none of the above

Question 16

At 900.0 K, the equilibrium constant (Kp)for the following reaction is 0.345. 2SO2 + O2 (g) → 2SO3 (g)
At equilibrium, the partial pressure of SO2 is 36.9 atm and that of O2 is 16.8 atm. The partial pressure of SO3 is ________ atm.

Accepted Answer

A) 88.8 
B) 3.89 × 10-3 
C) 214 
D) 5.57 × 10-4 
E) 42.4 
A) 88.8 
B) 3.89 × 10-3 
C) 214 
D) 5.57 × 10-4 
E) 42.4

Question 17

At 200 °C, the equilibrium constant (Kp)for the reaction below is 2.40 × 103. 2NO (g)   N2 (g) + O2 (g)
A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O2 is ________ atm.

Accepted Answer

A) 294 
B) 35.7 
C) 17.9 
D) 6.00 
E) 1.50 × 10-2 
A) 294 
B) 35.7 
C) 17.9 
D) 6.00 
E) 1.50 × 10-2

Question 18

If a reaction is endothermic, ________ the reaction temperature results in an increase in K.

Accepted Answer

The answer of If a reaction is endothermic, ________ the...

Question 19

The equilibrium expression for Kp for the reaction below is ________. 2O3 (g)   3O2 (g)

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 20

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? 2SO2 (g)+ O2 (g)   2SO3 (g)

Accepted Answer

A) [SO3] / [SO2][O2] 
B) [SO2] / [SO3] 
C) [SO3]2 / [SO2]2[O2] 
D) [SO3]2 / [SO2]2[O2]2 
E) [SO3] / [SO2][O2]2 
A) [SO3] / [SO2][O2] 
B) [SO2] / [SO3] 
C) [SO3]2 / [SO2]2[O2] 
D) [SO3]2 / [SO2]2[O2]2 
E) [SO3] / [SO2][O2]2

Exam 15: Chemical Equilibrium

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? CO2 (s) + H2O (l) H+ (aq) + HCO3- (aq)

Given the following reaction at equilibrium, if Kc = 5.84 x 105 at 230.0 °C, Kp = ________. 2NO (g) + O2 (g) 2NO2 (g)

The Keq for the equilibrium below is 0.112 at 700.0 °C. SO2 (g) + O2 (g) SO3 (g) What is the value of Keq at this temperature for the following reaction? 2SO3 (g) 2SO2 (g) + O2 (g)

Pure ________ and pure ________ are excluded from equilibrium-constant expressions.

Which of the following statements is true?

The equilibrium constant for the gas phase reaction 2SO2 (g) + O2 (g) 2SO3 (g) Is Keq = 2.80 × 102 at 999 K. At equilibrium, ________.

The equilibrium constant for the gas phase reaction N2 (g) + 3H2 (g) 2NH3 (g) Is Keq = 4.34 × 10-3 at 300 °C. At equilibrium, ________.

Consider the following reaction at equilibrium: 2SO2 (g) + O2 (g) 2SO3 (g)ΔH° = -99 kJ Le Châtelier's principle predicts that a(n)increase in temperature will result in ________.

The Keq for the equilibrium below is 7.52 × 10-2 at 480.0 °C. 2Cl2 (g) + 2H2O (g) 4HCl (g) + O2 (g) What is the value of Keq at this temperature for the following reaction? 2HCl (g) + O2 (g) Cl2 (g) + H2O (g)

The number obtained by substituting starting reactant and product concentrations into an equilibrium-constant expression is known as the ________.

Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g) 2 NO2 (g) A 1.00-L flask is charged with ofN2O4. At equilibrium at 373 K, 0.0055 mol of N2O4 remains. Keq for this reaction is ________.

Given the following reaction at equilibrium at 450.0 °C: CaCO3 (s) CaO (s) + CO2 (g) If pCO2 = 0.0155 atm, Kc = ________.

Consider the following reaction at equilibrium: 2NH3 (g) N2 (g) + 3H2 (g)ΔH° = +92.4 kJ Le Châtelier's principle predicts that removing N2 (g)to the system at equilibrium will result in ________.

The Keq for the equilibrium below is 0.112 at 700.0 °C. SO2 (g) + O2 (g) SO3 (g) What is the value of Keq at this temperature for the following reaction? SO3 (g) SO2 (g) + O2 (g)

The value of Keq for the equilibrium N2 (g) + O2 (g) 2 NO (g) Is 4.2 × 10-31 at 27 °C. What is the value of Keq for the equilibrium below? 4 NO (g) 2 N2 (g) + 2 O2 (g)

At 900.0 K, the equilibrium constant (Kp)for the following reaction is 0.345. 2SO2 + O2 (g) → 2SO3 (g) At equilibrium, the partial pressure of SO2 is 36.9 atm and that of O2 is 16.8 atm. The partial pressure of SO3 is ________ atm.

At 200 °C, the equilibrium constant (Kp)for the reaction below is 2.40 × 103. 2NO (g) N2 (g) + O2 (g) A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O2 is ________ atm.

If a reaction is endothermic, ________ the reaction temperature results in an increase in K.

The equilibrium expression for Kp for the reaction below is ________. 2O3 (g) 3O2 (g)

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? 2SO2 (g)+ O2 (g) 2SO3 (g)

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Which of the following expressions is the correct equilibrium-constant expression for the reaction below? CO₂ (s) + H₂O (l) H⁺ (aq) + HCO₃^- (aq)

Given the following reaction at equilibrium, if K_c = 5.84 x 10⁵at 230.0 °C, K_p = ________. 2NO (g) + O₂ (g) 2NO₂ (g)

The K_eq for the equilibrium below is 0.112 at 700.0 °C. SO₂ (g) + O₂(g) SO₃ (g) What is the value of K_eq at this temperature for the following reaction? 2SO₃ (g) 2SO₂ (g) + O₂ (g)

Pure and pure are excluded from equilibrium-constant expressions.

The equilibrium constant for the gas phase reaction 2SO₂ (g) + O₂ (g) 2SO₃ (g) Is K_eq = 2.80 × 10² at 999 K. At equilibrium, ________.

The equilibrium constant for the gas phase reaction N₂ (g) + 3H₂ (g) 2NH₃(g) Is K_eq = 4.34 × 10^-3 at 300 °C. At equilibrium, ________.

Consider the following reaction at equilibrium: 2SO₂ (g) + O₂ (g) 2SO₃(g)ΔH° = -99 kJ Le Châtelier's principle predicts that a(n)increase in temperature will result in ________.

The K_eq for the equilibrium below is 7.52 × 10^-2 at 480.0 °C. 2Cl₂ (g) + 2H₂O (g) 4HCl (g) + O₂ (g) What is the value of K_eq at this temperature for the following reaction? 2HCl (g) + O₂ (g) Cl₂ (g) + H₂O (g)

Dinitrogentetraoxide partially decomposes according to the following equilibrium: N₂O₄ (g) 2 NO₂ (g) A 1.00-L flask is charged with ofN₂O₄. At equilibrium at 373 K, 0.0055 mol of N₂O₄ remains. K_eq for this reaction is ________.

Given the following reaction at equilibrium at 450.0 °C: CaCO₃ (s) CaO (s) + CO₂ (g) If pCO₂ = 0.0155 atm, K_c = ________.

Consider the following reaction at equilibrium: 2NH₃ (g) N₂ (g) + 3H₂ (g)ΔH° = +92.4 kJ Le Châtelier's principle predicts that removing N₂ (g)to the system at equilibrium will result in ________.

The K_eq for the equilibrium below is 0.112 at 700.0 °C. SO₂ (g) + O₂ (g) SO₃ (g) What is the value of K_eq at this temperature for the following reaction? SO₃ (g) SO₂ (g) + O₂ (g)

The value of K_eq for the equilibrium N₂ (g) + O₂ (g) 2 NO (g) Is 4.2 × 10^-31 at 27 °C. What is the value of K_eq for the equilibrium below? 4 NO (g) 2 N₂ (g) + 2 O₂ (g)

At 900.0 K, the equilibrium constant (K_p)for the following reaction is 0.345. 2SO₂ + O₂ (g) → 2SO₃ (g) At equilibrium, the partial pressure of SO₂ is 36.9 atm and that of O₂ is 16.8 atm. The partial pressure of SO₃ is ________ atm.

At 200 °C, the equilibrium constant (K_p)for the reaction below is 2.40 × 10³. 2NO (g) N₂ (g) + O₂ (g) A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O₂ is ________ atm.

The equilibrium expression for K_p for the reaction below is ________. 2O₃(g) 3O₂(g)

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? 2SO₂ (g)+ O₂ (g) 2SO₃ (g)