Question 1

Write the mass-action expression,Qc ,for the following chemical reaction.
MgO(s)+ SO2(g)+  
O2(g)  
MgSO4(s)

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) None of these expressions is correct. 
A) 
  
B) 
  
C) 
  
D) 
  
E) None of these expressions is correct.

Question 2

For a solution equilibrium,a change in concentration of a reactant or product does not change Kc.

Accepted Answer

A) True 
 B)False

Question 3

a.State Le Chatelier's principle
b.The following reaction is at equilibrium in a closed container:
   
What effects,if any,will the following actions have on the position of equilibrium? In each case,state the direction of any shift in equilibrium,and give your reasons in one sentence.
(i)adding more Fe(OH)3
 (ii)raising the temperature
(iii)adding a catalyst

Accepted Answer

a.If a stress is applied to a system at

Question 4

The following reaction is at equilibrium at a pressure of 1 atm,in a closed container.
 
Which,if any,of the following actions will decrease the concentration of CO2 gas present at equilibrium?

Accepted Answer

A) adding N2 gas to double the pressure 
B) adding more solid NaOH 
C) increasing the volume of the container 
D) lowering the temperature 
E) None of these choices is correct. 
A) adding N2 gas to double the pressure 
B) adding more solid NaOH 
C) increasing the volume of the container 
D) lowering the temperature 
E) None of these choices is correct.

Question 5

At 25°C,the equilibrium constant Kc for the reaction in the solvent CCl4
 2BrCl  
Br2 + Cl2
 is 0.141.If the initial concentration of chlorine is 0.0300 M and of bromine monochloride is 0.0200 M,what is the equilibrium concentration of bromine?

Accepted Answer

A) 1.35 $\times$ 10-3 M 
B) 2.70 $\times$ 10-3 M 
C) 8.82 $\times$ 10-3 M 
D) 9.70 $\times$ 10-2 M 
E) None of these choices is correct. 
A) 1.35 $\times$ 10-3 M 
B) 2.70 $\times$ 10-3 M 
C) 8.82 $\times$ 10-3 M 
D) 9.70 $\times$ 10-2 M 
E) None of these choices is correct.

Question 6

When 0.152 mol of solid PH3BCl3 is introduced into a 3.0 L container at a certain temperature,8.44 $\times$ 10-3 mol of PH3 is present at equilibrium:
PH3BCl3(s)   
PH3(g)+ BCl3(g)
Construct a reaction table for the process,and use it to calculate Kc at this temperature.

Accepted Answer

@#IMG-DLM& K_c = (0.

Question 7

Compounds A,B,and C react according to the following equation.
3A(g)+ 2B(g)  
2C(g)
At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M,[B] = 1.23 M,and [C] = 1.75 M.What is the value of Kc for this reaction?

Accepted Answer

A) 0.309 
B) 0.601 
C) 1.66 
D) 3.24 
E) > 10 
A) 0.309 
B) 0.601 
C) 1.66 
D) 3.24 
E) > 10

Question 8

About half of the sodium carbonate produced is used in making glass products because it lowers the melting point of sand,the major component of glass.When sodium carbonate is added to water it hydrolyses according to the following reactions.
 
These can be combined to yield
 
What is the value of K3?

Accepted Answer

A) K1 $\times$ K2 
B) K1 $\times$ K2. 
C) K1 + K2 
D) K1 - K2 
E) (K1K2)2 
A) K1 $\times$ K2 
B) K1 $\times$ K2. 
C) K1 + K2 
D) K1 - K2 
E) (K1K2)2

Question 9

Sodium hydrogen carbonate decomposes above 110°C to form sodium carbonate,water,and carbon dioxide.
2NaHCO3(s)  
Na2CO3(s)+ H2O(g)+ CO2(g)
One thousand grams of sodium hydrogen carbonate are added to a reaction vessel,the temperature is increased to 200°C,and the system comes to equilibrium.What happens in this system if another 50 g of sodium carbonate are now added?

Accepted Answer

A) The partial pressure of carbon dioxide will increase. 
B) The partial pressure of carbon dioxide will decrease. 
C) The partial pressure of carbon dioxide will be unchanged. 
D) The amounts of all products will be greater when equilibrium is reestablished. 
E) None of these conclusions is justified without knowing the equilibrium constant. 
A) The partial pressure of carbon dioxide will increase. 
B) The partial pressure of carbon dioxide will decrease. 
C) The partial pressure of carbon dioxide will be unchanged. 
D) The amounts of all products will be greater when equilibrium is reestablished. 
E) None of these conclusions is justified without knowing the equilibrium constant.

Question 10

At 850°C,the equilibrium constant Kp for the reaction
C(s)+ CO2(g)  
2CO(g)
Has a value of 10.7.If the total pressure in the system at equilibrium is 1.000 atm,what is the partial pressure of carbon monoxide?

Accepted Answer

A) 0.362 atm 
B) 0.489 atm 
C) 0.667 atm 
D) 0.915 atm 
E) 0.921 atm 
A) 0.362 atm 
B) 0.489 atm 
C) 0.667 atm 
D) 0.915 atm 
E) 0.921 atm

Question 11

Consider the reactions of cadmium with the thiosulfate anion.
 
What is the value for the equilibrium constant for the following reaction?
Cd2+(aq)+ 2S2O32-(aq)  
Cd(S2O3)22-(aq)

Accepted Answer

A) 0.030 
B) 33 
C) 8.1 $\times$ 103 
D) 8.6 $\times$ 103 
E) 2.1 $\times$ 106 
A) 0.030 
B) 33 
C) 8.1 $\times$ 103 
D) 8.6 $\times$ 103 
E) 2.1 $\times$ 106

Question 12

Hydrogen bromide will dissociate into hydrogen and bromine gases.
 
What effect will a temperature increase of 50°C have on this system at equilibrium?

Accepted Answer

A) The partial pressure of hydrogen bromide will increase. 
B) The partial pressure of hydrogen will increase. 
C) The partial pressure of hydrogen bromide and bromine will increase. 
D) There will be no effect on the partial pressure of any of the gases. 
E) The initial pressure,volume and temperature must be known before any of the above predictions can be made. 
A) The partial pressure of hydrogen bromide will increase. 
B) The partial pressure of hydrogen will increase. 
C) The partial pressure of hydrogen bromide and bromine will increase. 
D) There will be no effect on the partial pressure of any of the gases. 
E) The initial pressure,volume and temperature must be known before any of the above predictions can be made.

Question 13

Write the expression for Kc and Kp for the reaction
PH3BCl3(s)   
PH3(g)+ BCl3(g)

Accepted Answer

K_c = [PH₃][B

Question 14

Nitrogen dioxide decomposes according to the reaction
2NO2(g)  
2NO(g)+ O2(g)
Where Kp = 4.48 $\times$ 10-13 at 25°C.What is the value for Kc?

Accepted Answer

A) 1.81 $\times$ 10-16 
B) 1.83 $\times$ 10-14 
C) 4.48 $\times$ 10-13 
D) 1.10 $\times$ 10-11 
E) 1.11 $\times$ 10-9 
A) 1.81 $\times$ 10-16 
B) 1.83 $\times$ 10-14 
C) 4.48 $\times$ 10-13 
D) 1.10 $\times$ 10-11 
E) 1.11 $\times$ 10-9

Question 15

Ammonia is synthesized in the Haber process:
N2(g)+ 3H2(g)   
2NH3(g)
Kp for this reaction is 1.49 $\times$ 10-5 atm-2 at 500.°C.Calculate Kc at this temperature.

Accepted Answer

K<sub>c</sub> = 6.00

Question 16

Which of the following has an effect on the magnitude of the equilibrium constant?

Accepted Answer

A) activation energy of the forward reaction 
B) concentrations of the reactants and products 
C) presence of a catalyst 
D) change in volume of container 
E) change in temperature 
A) activation energy of the forward reaction 
B) concentrations of the reactants and products 
C) presence of a catalyst 
D) change in volume of container 
E) change in temperature

Question 17

The equilibrium constant,Kp,has a value of 6.5 $\times$ 10-4 at 308 K for the reaction of nitrogen monoxide with chlorine.
2NO(g)+ Cl2(g)  
2NOCl(g)
What is the value of Kc?

Accepted Answer

A) 2.5 $\times$ 10-7 
B) 6.5 $\times$ 10-4 
C) 1.6 $\times$ 10-2 
D) 1.7 
E) None of these choices is correct. 
A) 2.5 $\times$ 10-7 
B) 6.5 $\times$ 10-4 
C) 1.6 $\times$ 10-2 
D) 1.7 
E) None of these choices is correct.

Question 18

Although a system may be at equilibrium,the rate constants of the forward and reverse reactions will in general be different.

Accepted Answer

A) True 
 B)False

Question 19

Methanol can be synthesized by combining carbon monoxide and hydrogen.
CO(g)+ 2H2(g)  
CH3OH(g)
A reaction vessel contains the three gases at equilibrium with a total pressure of 1.00 atm.What will happen to the partial pressure of hydrogen if enough argon is added to raise the total pressure to 1.4 atm?

Accepted Answer

A) The partial pressure of hydrogen will decrease. 
B) The partial pressure of hydrogen will increase. 
C) The partial pressure of hydrogen will be unchanged. 
D) Kp needs to be known before a prediction can be made. 
E) Both Kp and the temperature need to be known before a prediction can be made. 
A) The partial pressure of hydrogen will decrease. 
B) The partial pressure of hydrogen will increase. 
C) The partial pressure of hydrogen will be unchanged. 
D) Kp needs to be known before a prediction can be made. 
E) Both Kp and the temperature need to be known before a prediction can be made.

Question 20

Nitric oxide is formed in automobile exhaust when nitrogen and oxygen in air react at high temperatures.
N2(g)+ O2(g)  
2NO(g)
The equilibrium constant Kp for the reaction is 0.0025 at 2127°C.If a container is charged with 8.00 atm of nitrogen and 5.00 atm of oxygen and the mixture is allowed to reach equilibrium,what will be the equilibrium partial pressure of nitrogen?

Accepted Answer

A) 0.16 atm 
B) 0.31 atm 
C) 3.1 atm 
D) 7.7 atm 
E) 7.8 atm 
A) 0.16 atm 
B) 0.31 atm 
C) 3.1 atm 
D) 7.7 atm 
E) 7.8 atm

Write the mass-action expression,Q_c ,for the following chemical reaction. MgO(s)+ SO₂(g)+ O₂(g) MgSO₄(s)

For a solution equilibrium,a change in concentration of a reactant or product does not change K_c.

The following reaction is at equilibrium at a pressure of 1 atm,in a closed container. Which,if any,of the following actions will decrease the concentration of CO₂ gas present at equilibrium?

At 25°C,the equilibrium constant K_c for the reaction in the solvent CCl₄ 2BrCl Br₂ + Cl₂ is 0.141.If the initial concentration of chlorine is 0.0300 M and of bromine monochloride is 0.0200 M,what is the equilibrium concentration of bromine?

Compounds A,B,and C react according to the following equation. 3A(g)+ 2B(g) 2C(g) At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M,[B] = 1.23 M,and [C] = 1.75 M.What is the value of K_c for this reaction?

About half of the sodium carbonate produced is used in making glass products because it lowers the melting point of sand,the major component of glass.When sodium carbonate is added to water it hydrolyses according to the following reactions. These can be combined to yield What is the value of K₃?

At 850°C,the equilibrium constant K_p for the reaction C(s)+ CO₂(g) 2CO(g) Has a value of 10.7.If the total pressure in the system at equilibrium is 1.000 atm,what is the partial pressure of carbon monoxide?

Consider the reactions of cadmium with the thiosulfate anion. What is the value for the equilibrium constant for the following reaction? Cd²⁺(aq)+ 2S₂O₃^2-(aq) Cd(S₂O₃)₂^2-(aq)

Hydrogen bromide will dissociate into hydrogen and bromine gases. What effect will a temperature increase of 50°C have on this system at equilibrium?

Write the expression for K_c and K_p for the reaction PH₃BCl₃(s) PH₃(g)+ BCl₃(g)

Which of the following has an effect on the magnitude of the equilibrium constant?

Although a system may be at equilibrium,the rate constants of the forward and reverse reactions will in general be different.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids,solids,and Phase Changes

The Properties of Solutions

The Main-Group Elements: Applying Principles of Bonding and Structure

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Exam 17: Equilibrium: the Extent of Chemical Reactions

Write the mass-action expression,Qc ,for the following chemical reaction. MgO(s)+ SO2(g)+ O2(g) MgSO4(s)

For a solution equilibrium,a change in concentration of a reactant or product does not change Kc.

The following reaction is at equilibrium at a pressure of 1 atm,in a closed container. Which,if any,of the following actions will decrease the concentration of CO2 gas present at equilibrium?

At 25°C,the equilibrium constant Kc for the reaction in the solvent CCl4 2BrCl Br2 + Cl2 is 0.141.If the initial concentration of chlorine is 0.0300 M and of bromine monochloride is 0.0200 M,what is the equilibrium concentration of bromine?

When 0.152 mol of solid PH3BCl3 is introduced into a 3.0 L container at a certain temperature,8.44 ×\times× 10-3 mol of PH3 is present at equilibrium: PH3BCl3(s) PH3(g)+ BCl3(g) Construct a reaction table for the process,and use it to calculate Kc at this temperature.

Compounds A,B,and C react according to the following equation. 3A(g)+ 2B(g) 2C(g) At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M,[B] = 1.23 M,and [C] = 1.75 M.What is the value of Kc for this reaction?

About half of the sodium carbonate produced is used in making glass products because it lowers the melting point of sand,the major component of glass.When sodium carbonate is added to water it hydrolyses according to the following reactions. These can be combined to yield What is the value of K3?

At 850°C,the equilibrium constant Kp for the reaction C(s)+ CO2(g) 2CO(g) Has a value of 10.7.If the total pressure in the system at equilibrium is 1.000 atm,what is the partial pressure of carbon monoxide?

Consider the reactions of cadmium with the thiosulfate anion. What is the value for the equilibrium constant for the following reaction? Cd2+(aq)+ 2S2O32-(aq) Cd(S2O3)22-(aq)

Hydrogen bromide will dissociate into hydrogen and bromine gases. What effect will a temperature increase of 50°C have on this system at equilibrium?

Write the expression for Kc and Kp for the reaction PH3BCl3(s) PH3(g)+ BCl3(g)

Nitrogen dioxide decomposes according to the reaction 2NO2(g) 2NO(g)+ O2(g) Where Kp = 4.48 ×\times× 10-13 at 25°C.What is the value for Kc?

Ammonia is synthesized in the Haber process: N2(g)+ 3H2(g) 2NH3(g) Kp for this reaction is 1.49 ×\times× 10-5 atm-2 at 500.°C.Calculate Kc at this temperature.

Which of the following has an effect on the magnitude of the equilibrium constant?

The equilibrium constant,Kp,has a value of 6.5 ×\times× 10-4 at 308 K for the reaction of nitrogen monoxide with chlorine. 2NO(g)+ Cl2(g) 2NOCl(g) What is the value of Kc?

Although a system may be at equilibrium,the rate constants of the forward and reverse reactions will in general be different.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids,solids,and Phase Changes

The Properties of Solutions

The Main-Group Elements: Applying Principles of Bonding and Structure

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Write the mass-action expression,Q_c ,for the following chemical reaction. MgO(s)+ SO₂(g)+ O₂(g) MgSO₄(s)

For a solution equilibrium,a change in concentration of a reactant or product does not change K_c.

The following reaction is at equilibrium at a pressure of 1 atm,in a closed container. Which,if any,of the following actions will decrease the concentration of CO₂ gas present at equilibrium?

At 25°C,the equilibrium constant K_c for the reaction in the solvent CCl₄ 2BrCl Br₂ + Cl₂ is 0.141.If the initial concentration of chlorine is 0.0300 M and of bromine monochloride is 0.0200 M,what is the equilibrium concentration of bromine?

Compounds A,B,and C react according to the following equation. 3A(g)+ 2B(g) 2C(g) At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M,[B] = 1.23 M,and [C] = 1.75 M.What is the value of K_c for this reaction?

About half of the sodium carbonate produced is used in making glass products because it lowers the melting point of sand,the major component of glass.When sodium carbonate is added to water it hydrolyses according to the following reactions. These can be combined to yield What is the value of K₃?

At 850°C,the equilibrium constant K_p for the reaction C(s)+ CO₂(g) 2CO(g) Has a value of 10.7.If the total pressure in the system at equilibrium is 1.000 atm,what is the partial pressure of carbon monoxide?

Consider the reactions of cadmium with the thiosulfate anion. What is the value for the equilibrium constant for the following reaction? Cd²⁺(aq)+ 2S₂O₃^2-(aq) Cd(S₂O₃)₂^2-(aq)

Write the expression for K_c and K_p for the reaction PH₃BCl₃(s) PH₃(g)+ BCl₃(g)