Question 1

Based on Le Châtelier's principle,increasing pressure at constant temperature in the following reaction will not change the concentrations of reactants and products.

Accepted Answer

A) N2O4 (g)   2NO2 (g) 
B) N2 (g)+ O2 (g)   2NO (g) 
C) N2 (g)+ 2O2 (g)   2NO2 (g) 
D) N2 (g)+ 3H2 (g)   2NH3 (g) 
E) 2N2 (g)+ O2 (g)   2N2O (g) 
A) N2O4 (g)   2NO2 (g) 
B) N2 (g)+ O2 (g)   2NO (g) 
C) N2 (g)+ 2O2 (g)   2NO2 (g) 
D) N2 (g)+ 3H2 (g)   2NH3 (g) 
E) 2N2 (g)+ O2 (g)   2N2O (g)

Question 2

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 3

The value of   for the following reaction is 0.25: S   (g)+ N   (g)   S   (g)+ NO (g)
The value of   at the same temperature for the reaction below is ________.
3S   (g)+ 3N   (g)   3S   (g)+ 3NO (g)

Accepted Answer

A) 1.6 × 10-2 
B) 7.5 × 10-1 
C) 8.3 × 10-2 
D) 6.4 × 101 
E) 0.25 
A) 1.6 × 10-2 
B) 7.5 × 10-1 
C) 8.3 × 10-2 
D) 6.4 × 101 
E) 0.25

Question 4

Consider the following reaction at equilibrium: 2C   (g)   2CO (g)+   (g)ΔH° = -514 kJ
Le Châtelier's principle predicts that removing   (g)to the reaction container will ________.

Accepted Answer

A) increase the partial pressure of CO 
B) decrease the partial pressure of CO 
C) increase the partial pressure of CO2 
D) increase the value of the equilibrium constant 
E) decrease the value of the equilibrium constant 
A) increase the partial pressure of CO 
B) decrease the partial pressure of CO 
C) increase the partial pressure of CO2 
D) increase the value of the equilibrium constant 
E) decrease the value of the equilibrium constant

Question 5

Le Châtelier's principle states that if a system at equilibrium is disturbed,then more products are produced.

Accepted Answer

A) True 
 B)False

Question 6

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 7

Phosphorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to the reaction:   (g)+   (g)→   (g) An equilibrium mixture at 450 K contains   = 0.224 atm,   = 0.284 atm,and   = 4.24 atm.What is the value of Kp at this temperature?

Accepted Answer

A) 66.7 
B) 1.50 ×   
C) 2.70 × 10-1 
D) 3.74 
E) 8.36 
A) 66.7 
B) 1.50 ×   
C) 2.70 × 10-1 
D) 3.74 
E) 8.36

Question 8

In the coal-gasification process,carbon monoxide reacts with water to produce carbon dioxide and hydrogen gas.In an experiment,0.35 mol of CO and 0.40 mol of H2O were placed in a 1.00-L reaction vessel.At equilibrium,there were 0.22 mol of CO remaining.Keq at the temperature of the experiment is ________.

Accepted Answer

A) 5.5 
B) 0.28 
C) 0.75 
D) 3.5 
E) 1.0 
A) 5.5 
B) 0.28 
C) 0.75 
D) 3.5 
E) 1.0

Question 9

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 10

The expression for   for the reaction below is ________. 4CuO (s)+ CH4 (g)   CO2 (g)+ 4Cu (s)+ 2H2O (g)

Accepted Answer

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

Question 11

The value of Keq for the equilibrium H2 (g)+ I2 (g)   2HI (g)
Is 794 at 25 °C.What is the value of Keq for the equilibrium below?
1/2 H2 (g)+ 1/2 I2 (g)   HI (g)

Accepted Answer

A) 397 
B) 0.035 
C) 28 
D) 1588 
E) 0.0013 
A) 397 
B) 0.035 
C) 28 
D) 1588 
E) 0.0013

Question 12

The effect of a catalyst on a chemical reaction is to speed up the rate of the reaction in the forward direction by lowering the activation energy.

Accepted Answer

A) True 
 B)False

Question 13

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

Accepted Answer

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

Question 14

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

Accepted Answer

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

Question 15

The equilibrium constant for the gas phase reaction H2 (g)+ I2 (g)   2HI (g)
Is Keq = 50 at 25 °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 16

The equilibrium constant (Kp)for the interconversion of PCl5 and PCl3 is 0.0121.A vessel is charged with PCl5 giving an initial pressure of 0.123 atm and yields PCl3 and Cl2.At equilibrium,the partial pressure of PCl3 is ________ atm.

Accepted Answer

A) 0.0782 
B) 0.0330 
C) 0.0908 
D) 0.0455 
E) 0.123 
A) 0.0782 
B) 0.0330 
C) 0.0908 
D) 0.0455 
E) 0.123

Question 17

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 18

The equilibrium constant for reaction 1 is K.The equilibrium constant for reaction 2 is ________. (1)SO2 (g)+ (1/2)O2 (g)   SO3 (g)
(2)2SO3 (g)   2SO2 (g)+ O2 (g)

Accepted Answer

A) K2 
B) 2K 
C) 1/2K 
D) 1/K2 
E) -K2 
A) K2 
B) 2K 
C) 1/2K 
D) 1/K2 
E) -K2

Question 19

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

Accepted Answer

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

Question 20

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

Accepted Answer

A) True 
 B)False

Exam 15: Chemical Equilibrium

Based on Le Châtelier's principle,increasing pressure at constant temperature in the following reaction will not change the concentrations of reactants and products.

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

The value of for the following reaction is 0.25: S (g)+ N (g) S (g)+ NO (g) The value of at the same temperature for the reaction below is ________. 3S (g)+ 3N (g) 3S (g)+ 3NO (g)

Consider the following reaction at equilibrium: 2C (g) 2CO (g)+ (g)ΔH° = -514 kJ Le Châtelier's principle predicts that removing (g)to the reaction container will ________.

Le Châtelier's principle states that if a system at equilibrium is disturbed,then more products are produced.

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

Phosphorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to the reaction: (g)+ (g)→ (g) An equilibrium mixture at 450 K contains = 0.224 atm, = 0.284 atm,and = 4.24 atm.What is the value of Kp at this temperature?

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,________.

The expression for for the reaction below is ________. 4CuO (s)+ CH4 (g) CO2 (g)+ 4Cu (s)+ 2H2O (g)

The value of Keq for the equilibrium H2 (g)+ I2 (g) 2HI (g) Is 794 at 25 °C.What is the value of Keq for the equilibrium below? 1/2 H2 (g)+ 1/2 I2 (g) HI (g)

The effect of a catalyst on a chemical reaction is to speed up the rate of the reaction in the forward direction by lowering the activation energy.

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

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

The equilibrium constant for the gas phase reaction H2 (g)+ I2 (g) 2HI (g) Is Keq = 50 at 25 °C.At equilibrium,________.

The equilibrium constant (Kp)for the interconversion of PCl5 and PCl3 is 0.0121.A vessel is charged with PCl5 giving an initial pressure of 0.123 atm and yields PCl3 and Cl2.At equilibrium,the partial pressure of PCl3 is ________ atm.

Which of the following statements is true?

The equilibrium constant for reaction 1 is K.The equilibrium constant for reaction 2 is ________. (1)SO2 (g)+ (1/2)O2 (g) SO3 (g) (2)2SO3 (g) 2SO2 (g)+ O2 (g)

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

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

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

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Phosphorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to the reaction: (g)+ (g)→ (g) An equilibrium mixture at 450 K contains = 0.224 atm, = 0.284 atm,and = 4.24 atm.What is the value of K_p at this temperature?

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,________.

The expression for for the reaction below is ________. 4CuO (s)+ CH₄ (g) CO₂ (g)+ 4Cu (s)+ 2H₂O (g)

The value of K_eq for the equilibrium H₂ (g)+ I₂ (g) 2HI (g) Is 794 at 25 °C.What is the value of K_eq for the equilibrium below? 1/2 H₂ (g)+ 1/2 I₂ (g) HI (g)

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

The equilibrium constant for the gas phase reaction H₂ (g)+ I₂ (g) 2HI (g) Is K_eq = 50 at 25 °C.At equilibrium,________.

The equilibrium constant (K_p)for the interconversion of PCl₅ and PCl₃ is 0.0121.A vessel is charged with PCl₅ giving an initial pressure of 0.123 atm and yields PCl₃ and Cl₂.At equilibrium,the partial pressure of PCl₃ is ________ atm.

The equilibrium constant for reaction 1 is K.The equilibrium constant for reaction 2 is ________. (1)SO₂ (g)+ (1/2)O₂ (g) SO₃ (g) (2)2SO₃ (g) 2SO₂ (g)+ O₂ (g)