Question 1

Of the following equilibria, only ________ will shift to the left in response to a decrease in volume.

Accepted Answer

A) H2 (g) + Cl2 (g)   2 HCl (g) 
B) 2 SO3 (g)   2 SO2 (g) + O2 (g) 
C) N2 (g) + 3H2 (g)   2 NH3 (g) 
D) 4 Fe (s) + 3 O2 (g)   2 Fe2O3 (s) 
E) 2HI (g)   H2 (g) + I2 (g) 
A) H2 (g) + Cl2 (g)   2 HCl (g) 
B) 2 SO3 (g)   2 SO2 (g) + O2 (g) 
C) N2 (g) + 3H2 (g)   2 NH3 (g) 
D) 4 Fe (s) + 3 O2 (g)   2 Fe2O3 (s) 
E) 2HI (g)   H2 (g) + I2 (g) B

Question 2

A sealed 1.0 L flask is charged with 0.500 mol of I2 and 0.500 mol of Br2. An equilibrium reaction ensues: I2 (g) + Br2 (g)   2IBr (g)
When the container contents achieve equilibrium, the flask contains 0.84 mol of IBr. The value of Keq is ________.

Accepted Answer

A) 11 
B) 4.0 
C) 110 
D) 6.1 
E) 2.8 
A) 11 
B) 4.0 
C) 110 
D) 6.1 
E) 2.8 C

Question 3

Which one of the following will change the value of an equilibrium constant?

Accepted Answer

A) changing temperature 
B) adding other substances that do not react with any of the species involved in the equilibrium 
C) varying the initial concentrations of reactants 
D) varying the initial concentrations of products 
E) changing the volume of the reaction vessel 
A) changing temperature 
B) adding other substances that do not react with any of the species involved in the equilibrium 
C) varying the initial concentrations of reactants 
D) varying the initial concentrations of products 
E) changing the volume of the reaction vessel A

Question 4

The Keq for the equilibrium below is 5.4 × 1013 at 480.0 °C. 2NO (g) + O2 (g)   2NO2 (g)
What is the value of Keq at this temperature for the following reaction?
4NO (g) + 2O2 (g)   4NO2 (g)

Accepted Answer

A) 2.9 × 1027 
B) 8.5 × 1054 
C) 3.4 × 10-28 
D) -1.1 × 1014 
E) 5.4 × 1013 
A) 2.9 × 1027 
B) 8.5 × 1054 
C) 3.4 × 10-28 
D) -1.1 × 1014 
E) 5.4 × 1013

Question 5

If the reaction quotient Q for a reaction is greater than the value of the equilibrium constant K for that reaction at a given temperature, ________ must be converted to ________ for the system to reach equilibrium.

Accepted Answer

The answer of If the reaction quotient Q for a...

Question 6

Le Châtelier's principle states that if a system at equilibrium is disturbed, the equilibrium will shift to minimize the disturbance.

Accepted Answer

A) True 
 B)False

Question 7

Which one of the following is true concerning the Haber process?

Accepted Answer

A) It is a process used for shifting equilibrium positions to the right for more economical chemical synthesis of a variety of substances. 
B) It is a process used for the synthesis of ammonia. 
C) It is another way of stating Le Châtelier's principle. 
D) It is an industrial synthesis of sodium chloride that was discovered by Karl Haber. 
E) It is a process for the synthesis of elemental chlorine. 
A) It is a process used for shifting equilibrium positions to the right for more economical chemical synthesis of a variety of substances. 
B) It is a process used for the synthesis of ammonia. 
C) It is another way of stating Le Châtelier's principle. 
D) It is an industrial synthesis of sodium chloride that was discovered by Karl Haber. 
E) It is a process for the synthesis of elemental chlorine.

Question 8

The value of Keq for the following reaction is 0.16: A (g) + B (g)   C (g) + D (g)
The value of Keq at the same temperature for the reaction below is ________.
3C (g) + 3D (g)   3A (g) + 3B (g)

Accepted Answer

A) 2.4 × 102 
B) 2.1 
C) 4.1 × 10-3 
D) 5.3 × 10-2 
E) 6.3 
A) 2.4 × 102 
B) 2.1 
C) 4.1 × 10-3 
D) 5.3 × 10-2 
E) 6.3

Question 9

The equilibrium-constant expression for a reaction written in one direction is the ________ of the one for the reaction written for the reverse direction.

Accepted Answer

The answer of The equilibrium-constant expression for a reaction written...

Question 10

At 1000.0 K, the equilibrium constant for the reaction 2NO (g) + Br2 (g)   2NOBr (g)
Is Kp = 0.016. Calculate Kp for the reverse reaction,
2NOBr (g)   2NO (g) + Br2 (g).

Accepted Answer

A) 0.016 
B) 1.6 × 10-4 
C) 63 
D) 0.99 
E) 1.1 
A) 0.016 
B) 1.6 × 10-4 
C) 63 
D) 0.99 
E) 1.1

Question 11

In an exothermic equilibrium reaction, increasing the reaction temperature favors the formation of reactants.

Accepted Answer

A) True 
 B)False

Question 12

The value of Keq for the following reaction is 0.26: A (g) + B (g)   C (g) + D (g)
The value of Keq at the same temperature for the reaction below is ________.
2A (g) + 2B (g)   2C (g) + 2D (g)

Accepted Answer

A) 0.068 
B) 0.52 
C) 1.2 
D) 0.065 
E) 0.26 
A) 0.068 
B) 0.52 
C) 1.2 
D) 0.065 
E) 0.26

Question 13

How is the reaction quotient used to determine whether a system is at equilibrium?

Accepted Answer

A) The reaction quotient must be satisfied for equilibrium to be achieved. 
B) At equilibrium, the reaction quotient is undefined. 
C) The reaction is at equilibrium when Q eq. 
D) The reaction is at equilibrium when Q > Keq. 
E) The reaction is at equilibrium when Q = Keq. 
A) The reaction quotient must be satisfied for equilibrium to be achieved. 
B) At equilibrium, the reaction quotient is undefined. 
C) The reaction is at equilibrium when Q eq. 
D) The reaction is at equilibrium when Q > Keq. 
E) The reaction is at equilibrium when Q = Keq.

Question 14

Given the following reaction at equilibrium, if Kc = 1.90 × 1019 at 25.0 °C, Kp = ________. H2 (g) + Br2 (g)   2 HBr (g)

Accepted Answer

A) 5.26 × 10-20 
B) 1.56 × 104 
C) 6.44 × 105 
D) 1.90 × 1019 
E) none of the above 
A) 5.26 × 10-20 
B) 1.56 × 104 
C) 6.44 × 105 
D) 1.90 × 1019 
E) none of the above

Question 15

The relationship between the concentrations of reactants and products of a system at equilibrium is given by the law of mass action.

Accepted Answer

A) True 
 B)False

Question 16

Kp = 0.0198 at 721 K for the reaction 2HI (g)   H2 (g) + I2 (g)
In a particular experiment, the partial pressures of H2 and I2 at equilibrium are 0.678 and 0.788 atm, respectively. The partial pressure of HI is ________ atm.

Accepted Answer

A) 7.87 
B) 27.0 
C) 5.19 
D) 0.103 
E) 0.0106 
A) 7.87 
B) 27.0 
C) 5.19 
D) 0.103 
E) 0.0106

Question 17

The equilibrium constant for the gas phase reaction 2NH3 (g)   N2 (g) + 3H2 (g)
Is Keq = 230 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 18

Consider the following reaction at equilibrium: 2NH3 (g)   N2 (g) + 3H2 (g)
Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with ________.

Accepted Answer

A) some removal of NH3 from the reaction vessel (V and T constant) 
B) a decrease in the total pressure (T constant) 
C) addition of some N2 to the reaction vessel (V and T constant) 
D) a decrease in the total volume of the reaction vessel (T constant) 
E) an increase in total pressure by the addition of helium gas (V and T constant) 
A) some removal of NH3 from the reaction vessel (V and T constant) 
B) a decrease in the total pressure (T constant) 
C) addition of some N2 to the reaction vessel (V and T constant) 
D) a decrease in the total volume of the reaction vessel (T constant) 
E) an increase in total pressure by the addition of helium gas (V and T constant)

Question 19

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?
8HCl (g) + 2O2 (g)   4Cl2 (g) + 4H2O (g)

Accepted Answer

A) 1.77 × 102 
B) 5.66 × 10-3 
C) 1.50 × 10-1 
D) -7.52 × 10-2 
E) 7.52 × 10-2 
A) 1.77 × 102 
B) 5.66 × 10-3 
C) 1.50 × 10-1 
D) -7.52 × 10-2 
E) 7.52 × 10-2

Question 20

The equilibrium-constant expression for the reaction Ti (s) + 2Cl2 (g)   TiCl4 (l)
Is given by

Accepted Answer

A)    
B)    
C)    
D) [Cl2 (g)]-2  
E)    
A)    
B)    
C)    
D) [Cl2 (g)]-2  
E)

Exam 15: Chemical Equilibrium

Of the following equilibria, only ________ will shift to the left in response to a decrease in volume.

A sealed 1.0 L flask is charged with 0.500 mol of I2 and 0.500 mol of Br2. An equilibrium reaction ensues: I2 (g) + Br2 (g) 2IBr (g) When the container contents achieve equilibrium, the flask contains 0.84 mol of IBr. The value of Keq is ________.

Which one of the following will change the value of an equilibrium constant?

The Keq for the equilibrium below is 5.4 × 1013 at 480.0 °C. 2NO (g) + O2 (g) 2NO2 (g) What is the value of Keq at this temperature for the following reaction? 4NO (g) + 2O2 (g) 4NO2 (g)

If the reaction quotient Q for a reaction is greater than the value of the equilibrium constant K for that reaction at a given temperature, ________ must be converted to ________ for the system to reach equilibrium.

Le Châtelier's principle states that if a system at equilibrium is disturbed, the equilibrium will shift to minimize the disturbance.

Which one of the following is true concerning the Haber process?

The value of Keq for the following reaction is 0.16: A (g) + B (g) C (g) + D (g) The value of Keq at the same temperature for the reaction below is ________. 3C (g) + 3D (g) 3A (g) + 3B (g)

The equilibrium-constant expression for a reaction written in one direction is the ________ of the one for the reaction written for the reverse direction.

At 1000.0 K, the equilibrium constant for the reaction 2NO (g) + Br2 (g) 2NOBr (g) Is Kp = 0.016. Calculate Kp for the reverse reaction, 2NOBr (g) 2NO (g) + Br2 (g).

In an exothermic equilibrium reaction, increasing the reaction temperature favors the formation of reactants.

The value of Keq for the following reaction is 0.26: A (g) + B (g) C (g) + D (g) The value of Keq at the same temperature for the reaction below is ________. 2A (g) + 2B (g) 2C (g) + 2D (g)

How is the reaction quotient used to determine whether a system is at equilibrium?

Given the following reaction at equilibrium, if Kc = 1.90 × 1019 at 25.0 °C, Kp = ________. H2 (g) + Br2 (g) 2 HBr (g)

The relationship between the concentrations of reactants and products of a system at equilibrium is given by the law of mass action.

Kp = 0.0198 at 721 K for the reaction 2HI (g) H2 (g) + I2 (g) In a particular experiment, the partial pressures of H2 and I2 at equilibrium are 0.678 and 0.788 atm, respectively. The partial pressure of HI is ________ atm.

The equilibrium constant for the gas phase reaction 2NH3 (g) N2 (g) + 3H2 (g) Is Keq = 230 at 300 °C. At equilibrium, ________.

Consider the following reaction at equilibrium: 2NH3 (g) N2 (g) + 3H2 (g) Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with ________.

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? 8HCl (g) + 2O2 (g) 4Cl2 (g) + 4H2O (g)

The equilibrium-constant expression for the reaction Ti (s) + 2Cl2 (g) TiCl4 (l) Is given by

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A sealed 1.0 L flask is charged with 0.500 mol of I₂ and 0.500 mol of Br₂. An equilibrium reaction ensues: I₂ (g) + Br₂ (g) 2IBr (g) When the container contents achieve equilibrium, the flask contains 0.84 mol of IBr. The value of K_eq is ________.

The K_eq for the equilibrium below is 5.4 × 10¹³ at 480.0 °C. 2NO (g) + O₂ (g) 2NO₂ (g) What is the value of K_eq at this temperature for the following reaction? 4NO (g) + 2O₂ (g) 4NO₂ (g)

If the reaction quotient Q for a reaction is greater than the value of the equilibrium constant K for that reaction at a given temperature, must be converted to for the system to reach equilibrium.

The value of K_eq for the following reaction is 0.16: A (g) + B (g) C (g) + D (g) The value of K_eq at the same temperature for the reaction below is ________. 3C (g) + 3D (g) 3A (g) + 3B (g)

At 1000.0 K, the equilibrium constant for the reaction 2NO (g) + Br₂ (g) 2NOBr (g) Is K_p = 0.016. Calculate K_p for the reverse reaction, 2NOBr (g) 2NO (g) + Br₂(g).

The value of K_eq for the following reaction is 0.26: A (g) + B (g) C (g) + D (g) The value of K_eq at the same temperature for the reaction below is ________. 2A (g) + 2B (g) 2C (g) + 2D (g)

Given the following reaction at equilibrium, if K_c = 1.90 × 10¹⁹at 25.0 °C, K_p = ________. H₂ (g) + Br₂ (g) 2 HBr (g)

K_p = 0.0198 at 721 K for the reaction 2HI (g) H₂ (g) + I₂ (g) In a particular experiment, the partial pressures of H₂ and I₂ at equilibrium are 0.678 and 0.788 atm, respectively. The partial pressure of HI is ________ atm.

The equilibrium constant for the gas phase reaction 2NH₃ (g) N₂ (g) + 3H₂ (g) Is K_eq = 230 at 300 °C. At equilibrium, ________.

Consider the following reaction at equilibrium: 2NH₃ (g) N₂ (g) + 3H₂ (g) Le Châtelier's principle predicts that the moles of H₂ in the reaction container will increase with ________.

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? 8HCl (g) + 2O₂ (g) 4Cl₂ (g) + 4H₂O (g)

The equilibrium-constant expression for the reaction Ti (s) + 2Cl₂(g) TiCl₄(l) Is given by