Question 1

Reaction quotient Q will always be equal to the reaction's equilibrium constant K.

Accepted Answer

A) True 
 B)False

Question 2

Dinitrogen tetroxide partially decomposes according to the following equilibrium: 
    (g)⇌   (g) 
A 1.000 L flask is charged with 3.00 × 10-2 mol of     .At equilibrium,2.36 × 10-2 mol of     Remains.   For this reaction is:

Accepted Answer

A) 0.723 mol L-1 
B) 0.391 mol L-1 
C) 0.212 mol L-1 
D) 6.94 ×   mol L-1 
E) 1.92 × 10-4 mol L-1 
A) 0.723 mol L-1 
B) 0.391 mol L-1 
C) 0.212 mol L-1 
D) 6.94 ×   mol L-1 
E) 1.92 × 10-4 mol L-1

Question 3

Which of the following keep the equilibrium position unchanged?

Accepted Answer

A) temperature decrease 
B) concentration change 
C) temperature 
D) pressure change 
E) homogeneous catalyst 
A) temperature decrease 
B) concentration change 
C) temperature 
D) pressure change 
E) homogeneous catalyst

Question 4

For the reaction: CH4(g)+ 2 H2O(g)⇌ CO2(g)+ 4 H2(g),ΔrH° = +190 kJ,add N2(g)at constant volume and:

Accepted Answer

A) the reaction reacts to the right 
B) the reaction reacts to the left 
C) the ΔH° increases 
D) the temperature increases 
E) there is no change 
A) the reaction reacts to the right 
B) the reaction reacts to the left 
C) the ΔH° increases 
D) the temperature increases 
E) there is no change

Question 5

Consider the following equilibrium.
A(g)+ 3 B(g)⇌ 2 C(g)
If the initial concentrations are [A] = 1.00 M,[B] = 3.00 M,and [C] = 0,at equilibrium it is found that [C] = 0.980 M.Calculate Kc for this reaction.

Accepted Answer

A) 0.526 
B) 0.268 
C) 1.26 
D) 0.131 
E) 1.901 
A) 0.526 
B) 0.268 
C) 1.26 
D) 0.131 
E) 1.901

Question 6

For the reaction: 2 Cl2(g)+ 2 H2O(g)⇌ 4 HCl(g)+ O2(g),Kp = 6.4 × 10-6 at 500 K.If a fixed volume is filled with initial concentrations of these gases at 227 °C such that [Cl2] = 0.5 M,[H2O] = 0.40 M,[HCl] = 0.5 M,and [O2] = 0.015 M,in which direction will the reaction proceed?

Accepted Answer

A) The reaction proceeds to the right. 
B) The reaction proceeds to the left. 
C) The reaction is already at equilibrium. 
D) The reaction volume must be specified to answer this question. 
E) The value of Kp at 25 °C must be specified to answer this question. 
A) The reaction proceeds to the right. 
B) The reaction proceeds to the left. 
C) The reaction is already at equilibrium. 
D) The reaction volume must be specified to answer this question. 
E) The value of Kp at 25 °C must be specified to answer this question.

Question 7

For the decomposition of SO3(g),Kc = [SO2]2[O2]/[SO3]2,at equilibrium,there are 0.090 mol SO2,0.110 mol O2,0.100 mol SO3 in a 25.0-L container.What is the value of Kc?

Accepted Answer

A) 3.6 × 10-3  
B) 0.040 
C) 2.23 
D) 0.089 
E) 7.89 
A) 3.6 × 10-3  
B) 0.040 
C) 2.23 
D) 0.089 
E) 7.89

Question 8

Consider the exothermic reaction:
4 HCl(aq)+ MnO2(s)⇌ Cl2(g)+ 2 H2O(l)+ MnCl2(aq)
The equilibrium is displaced to the left if:

Accepted Answer

A) catalyst is added 
B) pressure is lowered 
C) temperature is lowered 
D) MnCl2(aq)is added 
E) MnO2(s)is added 
A) catalyst is added 
B) pressure is lowered 
C) temperature is lowered 
D) MnCl2(aq)is added 
E) MnO2(s)is added

Question 9

Consider the following reaction.
C(s)+ H2O(g)⇌ CO(g)+ H2(g)
At equilibrium at a certain temperature,[H2O] = 0.12 M,and [CO] = [H2] = 1.2 M.If suddenly these concentrations are increased by 0.50 M,which of the following is true?

Accepted Answer

A) more products are formed 
B) Kc = 4.66 
C) more H2O(g)will be formed 
D) Since Kc does not change,nothing happens. 
A) more products are formed 
B) Kc = 4.66 
C) more H2O(g)will be formed 
D) Since Kc does not change,nothing happens.

Question 10

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 for the reaction:
2 CO(g)+ O2(g)⇌ 2 CO2(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 11

At a certain temperature,Kc equals 1.40 × 102 M-1 for the reaction:
2 CO(g)+ O2(g)⇌ 2 CO2(g)
If a 3.00 L flask contains 0.400 mol of CO2 and 0.100 mol of O2 at equilibrium,how many moles of CO are also present in the flask?

Accepted Answer

A) 0.555 mol 
B) 0.185 mol 
C) 0.107 mol 
D) 0.0114 mol 
A) 0.555 mol 
B) 0.185 mol 
C) 0.107 mol 
D) 0.0114 mol

Question 12

Consider the equilibrium system: N2O4(g)⇌ 2 NO2(g)for which Kp = 0.1134 at 25 °C and ΔrH° = 58.03 kJ/mol.Assuming that the total pressure inside the container is 1.00 atm at equilibrium and that initially only N2O4 was present inside the container,compute  
At equilibrium.

Accepted Answer

A) 0.398 atm 
B) 0.113 atm 
C) 0.602 atm 
D) 0.285 atm 
E) 0.715 atm 
A) 0.398 atm 
B) 0.113 atm 
C) 0.602 atm 
D) 0.285 atm 
E) 0.715 atm

Question 13

Choose the correct statement about the equilibrium:
N2(g)+ 3 H2(g)⇌ 2 NH3(g),Kp = 1 × 10-4

Accepted Answer

A) The rate constant for the forward reaction is greater than that of the reverse reaction. 
B) Since the reaction has a high activation energy,a catalyst is not needed. 
C) The equilibrium constant is given by Kp = [N2][H2]3/[NH3]2. 
D) Conducting the reaction under high pressures will increase the yield of ammonia. 
E) The Kp is independent of temperature. 
A) The rate constant for the forward reaction is greater than that of the reverse reaction. 
B) Since the reaction has a high activation energy,a catalyst is not needed. 
C) The equilibrium constant is given by Kp = [N2][H2]3/[NH3]2. 
D) Conducting the reaction under high pressures will increase the yield of ammonia. 
E) The Kp is independent of temperature.

Question 14

For the reaction 2 A(g)⇌ B(g)+ C(g),Kc = 1.25 at 300 K.If a 1.00 L mixture contains 0.619 mol A,0.693 mol B,and 0.689 mol C at 300 K,will the mixture be in equilibrium? If not,in what direction will a net reaction occur?

Accepted Answer

A) Yes,reaction is at equilibrium. 
B) No,net reaction proceeds to the left. 
C) No,net reaction proceeds to the right. 
D) No,but there is no net reaction. 
E) Yes,net reaction proceeds to the right 
A) Yes,reaction is at equilibrium. 
B) No,net reaction proceeds to the left. 
C) No,net reaction proceeds to the right. 
D) No,but there is no net reaction. 
E) Yes,net reaction proceeds to the right

Question 15

For the reaction: 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g)what is the effect on equilibrium of increasing temperature of an exothermic reaction?

Accepted Answer

A) The reaction shifts to the right. 
B) There is no change. 
C) The reaction shifts to the left. 
D) The Kp is decreased. 
E) The Kp is doubled. 
A) The reaction shifts to the right. 
B) There is no change. 
C) The reaction shifts to the left. 
D) The Kp is decreased. 
E) The Kp is doubled.

Question 16

For the reaction: CH4(g)+ 2 H2O(g)⇌ CO2(g)+ 4 H2(g),ΔrH° = +190 kJ,when catalyst is added:

Accepted Answer

A) the reaction shifts to the right 
B) the reaction shifts to the left 
C) the ΔH° increases 
D) the temperature increases 
E) there is no change,catalyst changes reaction rate only 
A) the reaction shifts to the right 
B) the reaction shifts to the left 
C) the ΔH° increases 
D) the temperature increases 
E) there is no change,catalyst changes reaction rate only

Question 17

Which factor influences the value of the equilibrium constant for a reversible reaction?

Accepted Answer

A) addition of a catalyst 
B) raising the temperature 
C) removing product 
D) removing reactant 
E) increase in mixing rate 
A) addition of a catalyst 
B) raising the temperature 
C) removing product 
D) removing reactant 
E) increase in mixing rate

Question 18

In an equilibrium process,the concentrations of products and of reactants are equal.

Accepted Answer

A) True 
 B)False

Question 19

For the reaction: 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g)what is the effect of removing H2?

Accepted Answer

A) The reaction shifts to the right. 
B) There is no change. 
C) The reaction shifts to the left. 
D) The Kp is decreased. 
E) The Kp is doubled. 
A) The reaction shifts to the right. 
B) There is no change. 
C) The reaction shifts to the left. 
D) The Kp is decreased. 
E) The Kp is doubled.

Question 20

For the production of NO2,Kc = [NO2]2/[NO]2[O2].At equilibrium in a 2.50 L container,there are 3.00 mol NO,4.00 mol O2 and 22.0 mol NO2.The value of Kc is ________.

Accepted Answer

A) 13.4 
B) 33.6 
C) 5.38 
D) 0.0116 
E) 3.75 
A) 13.4 
B) 33.6 
C) 5.38 
D) 0.0116 
E) 3.75

Exam 15: Principles of Chemical Equilibrium

Reaction quotient Q will always be equal to the reaction's equilibrium constant K.

Dinitrogen tetroxide partially decomposes according to the following equilibrium: (g)⇌ (g) A 1.000 L flask is charged with 3.00 × 10-2 mol of .At equilibrium,2.36 × 10-2 mol of Remains. For this reaction is:

Which of the following keep the equilibrium position unchanged?

For the reaction: CH4(g)+ 2 H2O(g)⇌ CO2(g)+ 4 H2(g),ΔrH° = +190 kJ,add N2(g)at constant volume and:

Consider the following equilibrium. A(g)+ 3 B(g)⇌ 2 C(g) If the initial concentrations are [A] = 1.00 M,[B] = 3.00 M,and [C] = 0,at equilibrium it is found that [C] = 0.980 M.Calculate Kc for this reaction.

For the reaction: 2 Cl2(g)+ 2 H2O(g)⇌ 4 HCl(g)+ O2(g),Kp = 6.4 × 10-6 at 500 K.If a fixed volume is filled with initial concentrations of these gases at 227 °C such that [Cl2] = 0.5 M,[H2O] = 0.40 M,[HCl] = 0.5 M,and [O2] = 0.015 M,in which direction will the reaction proceed?

For the decomposition of SO3(g),Kc = [SO2]2[O2]/[SO3]2,at equilibrium,there are 0.090 mol SO2,0.110 mol O2,0.100 mol SO3 in a 25.0-L container.What is the value of Kc?

Consider the exothermic reaction: 4 HCl(aq)+ MnO2(s)⇌ Cl2(g)+ 2 H2O(l)+ MnCl2(aq) The equilibrium is displaced to the left if:

Consider the following reaction. C(s)+ H2O(g)⇌ CO(g)+ H2(g) At equilibrium at a certain temperature,[H2O] = 0.12 M,and [CO] = [H2] = 1.2 M.If suddenly these concentrations are increased by 0.50 M,which of the following is true?

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 for the reaction: 2 CO(g)+ O2(g)⇌ 2 CO2(g) What is the equilibrium concentration of CO?

At a certain temperature,Kc equals 1.40 × 102 M-1 for the reaction: 2 CO(g)+ O2(g)⇌ 2 CO2(g) If a 3.00 L flask contains 0.400 mol of CO2 and 0.100 mol of O2 at equilibrium,how many moles of CO are also present in the flask?

Consider the equilibrium system: N2O4(g)⇌ 2 NO2(g)for which Kp = 0.1134 at 25 °C and ΔrH° = 58.03 kJ/mol.Assuming that the total pressure inside the container is 1.00 atm at equilibrium and that initially only N2O4 was present inside the container,compute At equilibrium.

Choose the correct statement about the equilibrium: N2(g)+ 3 H2(g)⇌ 2 NH3(g),Kp = 1 × 10-4

For the reaction 2 A(g)⇌ B(g)+ C(g),Kc = 1.25 at 300 K.If a 1.00 L mixture contains 0.619 mol A,0.693 mol B,and 0.689 mol C at 300 K,will the mixture be in equilibrium? If not,in what direction will a net reaction occur?

For the reaction: 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g)what is the effect on equilibrium of increasing temperature of an exothermic reaction?

For the reaction: CH4(g)+ 2 H2O(g)⇌ CO2(g)+ 4 H2(g),ΔrH° = +190 kJ,when catalyst is added:

Which factor influences the value of the equilibrium constant for a reversible reaction?

In an equilibrium process,the concentrations of products and of reactants are equal.

For the reaction: 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g)what is the effect of removing H2?

For the production of NO2,Kc = [NO2]2/[NO]2[O2].At equilibrium in a 2.50 L container,there are 3.00 mol NO,4.00 mol O2 and 22.0 mol NO2.The value of Kc is ________.

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Acids and Bases

Additional Aspects of Acidbase Equilibria

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

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Dinitrogen tetroxide partially decomposes according to the following equilibrium: (g)⇌ (g) A 1.000 L flask is charged with 3.00 × 10^-2 mol of .At equilibrium,2.36 × 10^-2 mol of Remains. For this reaction is:

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),Δ_rH° = +190 kJ,add N₂(g)at constant volume and:

Consider the following equilibrium. A(g)+ 3 B(g)⇌ 2 C(g) If the initial concentrations are [A] = 1.00 M,[B] = 3.00 M,and [C] = 0,at equilibrium it is found that [C] = 0.980 M.Calculate K_c for this reaction.

For the reaction: 2 Cl₂(g)+ 2 H₂O(g)⇌ 4 HCl(g)+ O₂(g),K_p = 6.4 × 10^-6 at 500 K.If a fixed volume is filled with initial concentrations of these gases at 227 °C such that [Cl₂] = 0.5 M,[H₂O] = 0.40 M,[HCl] = 0.5 M,and [O₂] = 0.015 M,in which direction will the reaction proceed?

For the decomposition of SO₃(g),K_c = [SO₂]²[O₂]/[SO₃]²,at equilibrium,there are 0.090 mol SO₂,0.110 mol O₂,0.100 mol SO₃ in a 25.0-L container.What is the value of K_c?

Consider the exothermic reaction: 4 HCl(aq)+ MnO₂(s)⇌ Cl₂(g)+ 2 H₂O(l)+ MnCl₂(aq) The equilibrium is displaced to the left if:

Consider the following reaction. C(s)+ H₂O(g)⇌ CO(g)+ H₂(g) At equilibrium at a certain temperature,[H₂O] = 0.12 M,and [CO] = [H₂] = 1.2 M.If suddenly these concentrations are increased by 0.50 M,which of the following is true?

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 for the reaction: 2 CO(g)+ O₂(g)⇌ 2 CO₂(g) What is the equilibrium concentration of CO?

At a certain temperature,K_c equals 1.40 × 10² M^-1for the reaction: 2 CO(g)+ O₂(g)⇌ 2 CO₂(g) If a 3.00 L flask contains 0.400 mol of CO₂ and 0.100 mol of O₂ at equilibrium,how many moles of CO are also present in the flask?

Consider the equilibrium system: N₂O₄(g)⇌ 2 NO₂(g)for which K_p = 0.1134 at 25 °C and Δ_rH° = 58.03 kJ/mol.Assuming that the total pressure inside the container is 1.00 atm at equilibrium and that initially only N₂O₄ was present inside the container,compute At equilibrium.

Choose the correct statement about the equilibrium: N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g),K_p = 1 × 10^-4

For the reaction 2 A(g)⇌ B(g)+ C(g),K_c = 1.25 at 300 K.If a 1.00 L mixture contains 0.619 mol A,0.693 mol B,and 0.689 mol C at 300 K,will the mixture be in equilibrium? If not,in what direction will a net reaction occur?

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)what is the effect on equilibrium of increasing temperature of an exothermic reaction?

For the reaction: CH₄(g)+ 2 H₂O(g)⇌ CO₂(g)+ 4 H₂(g),Δ_rH° = +190 kJ,when catalyst is added:

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)what is the effect of removing H₂?

For the production of NO₂,K_c = [NO₂]²/[NO]²[O₂].At equilibrium in a 2.50 L container,there are 3.00 mol NO,4.00 mol O₂ and 22.0 mol NO₂.The value of K_c is ________.