Question 1

What is the Kc equilibrium-constant expression for the following equilibrium? NiO(s)+ H2(g)   Ni(s)+ H2O(g)

Accepted Answer

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

Question 2

Which of the following expressions for K is correct for the reaction given below? Al3+(aq)+ 4 OH-(aq)   Al(OH)4-(aq)

Accepted Answer

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

Question 3

Given the equilibrium constants for the following reactions: 4Cu(s)+ O2(g)   2Cu2O(s),K1
4CuO(s)   2Cu2O(s)+ O2(g),K2
What is K for the system
2Cu(s)+ O2(g)   2CuO(s)
Equivalent to?

Accepted Answer

A)      
B)    
C)  (K1)(K2) 
D)      
E)    
A)      
B)    
C)  (K1)(K2) 
D)      
E)    A

Question 4

What is the expression for Kc for the following equilibrium? CaSO3(s)   CaO(s)+ SO2(g)

Accepted Answer

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

Question 5

A 2.5 L flask is filled with 0.25 mol SO3,0.20 mol SO2,and 0.40 mol O2,and allowed to reach equilibrium.Assume the temperature of the mixture is chosen so that Kc = 0.12.Predict the effect on the concentration of SO3 as equilibrium is achieved by using Q,the reaction quotient. 2 SO3(g)   2 SO2(g)+ O2(g)

Accepted Answer

A)  [SO3] will decrease because Q > K. 
B)  [SO3] will decrease because Q 3] will increase because Q 3] will increase because Q > K. 
E)  [SO3] will remain the same because Q = K. 
A)  [SO3] will decrease because Q > K. 
B)  [SO3] will decrease because Q 3] will increase because Q 3] will increase because Q > K. 
E)  [SO3] will remain the same because Q = K.

Question 6

For the reaction given below,2.00 moles of A and 3.00 moles of B are placed in a 6.00-L container. A(g)+ 2B(g)   C(g)
At equilibrium,the concentration of A is 0.230 mol/L.What is the value of Kc?

Accepted Answer

A)  1.20 
B)  1.53 
C)  5.22 
D)  0.230 
E)  0.449 
A)  1.20 
B)  1.53 
C)  5.22 
D)  0.230 
E)  0.449

Question 7

The reaction quotient,Q,for a system is   .If the equilibrium constant for the system at some temperature is   ,what will happen as the reaction mixture returns to equilibrium?

Accepted Answer

A)  The equilibrium constant will increase until it equals the reaction quotient. 
B)  There will be a net loss in both product(s)and reactant(s). 
C)  There will be a net loss in product(s). 
D)  There will be a net loss in reactant(s). 
E)  The equilibrium constant will increase. 
A)  The equilibrium constant will increase until it equals the reaction quotient. 
B)  There will be a net loss in both product(s)and reactant(s). 
C)  There will be a net loss in product(s). 
D)  There will be a net loss in reactant(s). 
E)  The equilibrium constant will increase.

Question 8

When 1.0 mole of acetic acid is diluted with water to a volume of 1.0 L at 25 °C,0.42% of the acetic acid ionizes to form acetate ion and hydronium ion.
CH3CO2H(aq)+ H2O(   )   CH3CO2-(aq)+ H3O+(aq)
What percentage of the acid ionizes when 0.75 mole of acetic acid is diluted with water to 1.0 L at 25 °C?

Accepted Answer

Question 9

Which of the following is the correct balanced equation for the equilibrium expression given below?

Accepted Answer

A)  2 SO2(g)+ O2(g)   2 SO3(g) 
B)  2 SO3(g)   2 SO2(g)+ O2(g) 
C)  2 SO3(aq)   2 SO2(aq)+ O2(aq) 
D)  2 SO2(aq)+ O2(aq)   2 SO3(aq) 
E)  SO2(g)+   O2(g)   SO3(g) 
A)  2 SO2(g)+ O2(g)   2 SO3(g) 
B)  2 SO3(g)   2 SO2(g)+ O2(g) 
C)  2 SO3(aq)   2 SO2(aq)+ O2(aq) 
D)  2 SO2(aq)+ O2(aq)   2 SO3(aq) 
E)  SO2(g)+   O2(g)   SO3(g)

Question 10

If the reaction quotient,Q,is equal to K in a gas phase reaction,then

Accepted Answer

A)  the chemical system has reached equilibrium. 
B)  the temperature must be increased for the reaction to proceed in the forward direction. 
C)  the reaction will proceed in the forward direction until equilibrium is established. 
D)  the reaction will proceed in the backward direction until equilibrium is established. 
E)  the reaction will proceed in the direction that increases the number of gas phase particles. 
A)  the chemical system has reached equilibrium. 
B)  the temperature must be increased for the reaction to proceed in the forward direction. 
C)  the reaction will proceed in the forward direction until equilibrium is established. 
D)  the reaction will proceed in the backward direction until equilibrium is established. 
E)  the reaction will proceed in the direction that increases the number of gas phase particles.

Question 11

Which of the following is always true for a reaction where Kc is   at 25°C?

Accepted Answer

A)  The reaction mixture contains mostly reactants at equilibrium. 
B)  The reaction mixture contains mostly products at equilibrium. 
C)  The rate of reaction is very slow. 
D)  There are approximately equal moles of reactants and products at equilibrium. 
E)  Both A and C. 
A)  The reaction mixture contains mostly reactants at equilibrium. 
B)  The reaction mixture contains mostly products at equilibrium. 
C)  The rate of reaction is very slow. 
D)  There are approximately equal moles of reactants and products at equilibrium. 
E)  Both A and C.

Question 12

In which of the following reactions does a decrease in the volume of the reaction vessel at constant temperature favor the formation of the products?

Accepted Answer

A)  2 H2(g)+ O2(g)   2 H2O(g) 
B)  NO2(g)+ CO(g)   NO(g)+ CO2(g) 
C)  H2(g)+ I2(g)   2 HI(g) 
D)  2 O3(g)   3 O2(g) 
E)  MgCO3(s)   MgO(s)+ CO2(g) 
A)  2 H2(g)+ O2(g)   2 H2O(g) 
B)  NO2(g)+ CO(g)   NO(g)+ CO2(g) 
C)  H2(g)+ I2(g)   2 HI(g) 
D)  2 O3(g)   3 O2(g) 
E)  MgCO3(s)   MgO(s)+ CO2(g)

Question 13

What is the reaction quotient,Q,for the equilibrium CuCl(s)   Cu+(aq)+ Cl−(aq)
When 0.3746 L of   M Cu+ is combined with 0.4326 L of   M Cl− in the presence of an excess of CuCl(s)?

Accepted Answer

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

Question 14

Consider the reaction A(aq)   2 B(aq)where Kc = 4.1 at 25 °C.If 0.50 M A(aq)and 1.5 M B(aq)are initially present in a 1.0 L flask at 25 °C,what change in concentrations (if any)will occur in time?

Accepted Answer

A)  [A] will decrease and [B] will decrease. 
B)  [A] will decrease and [B] will increase. 
C)  [A] will increase and [B] will decrease. 
D)  [A] will increase and [B] will increase. 
E)  [A] and [B] remain unchanged. 
A)  [A] will decrease and [B] will decrease. 
B)  [A] will decrease and [B] will increase. 
C)  [A] will increase and [B] will decrease. 
D)  [A] will increase and [B] will increase. 
E)  [A] and [B] remain unchanged.

Question 15

The equilibrium constant (Kc)for the decomposition of ammonium hydrogen sulfide,NH4HS(s)   NH3(g)+ H2S(g),is 1.8 × 10-4 at 25 °C.If excess NH4HS(s)is allowed to equilibrate at 25 °C,what is the equilibrium concentration of NH3?

Accepted Answer

A)  3.2 × 10-8 M 
B)  9.0 × 10-5 M 
C)  1.8 × 10-4 M 
D)  6.7 × 10-3 M 
E)  1.3 × 10-2 M 
A)  3.2 × 10-8 M 
B)  9.0 × 10-5 M 
C)  1.8 × 10-4 M 
D)  6.7 × 10-3 M 
E)  1.3 × 10-2 M

Question 16

In 1913,the Haber-Bosch process was patented.The product of the Haber-Bosch process is ________.

Accepted Answer

The answer of In 1913,the Haber-Bosch process was patented.The product...

Question 17

For the equilibrium PCl5(g)   PCl3(g)+ Cl2(g),Kc = 4.0 at 228°C.If pure PCl5 is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl5(g)is 0.19 M,what is the equilibrium concentration of PCl3?

Accepted Answer

A)  0.095 M 
B)  0.4 M 
C)  0.19 M 
D)  0.87 M 
E)  0.009 M 
A)  0.095 M 
B)  0.4 M 
C)  0.19 M 
D)  0.87 M 
E)  0.009 M

Question 18

At a given temperature,K = 0.024 for the equilibrium: PCl5(g)   PCl3(g)+ Cl2(g)
What is K for:
Cl2(g)+ PCl3(g)   PCl5(g)?

Accepted Answer

A)  1700 
B)  24 
C)  0.00058 
D)  42 
E)  0.024 
A)  1700 
B)  24 
C)  0.00058 
D)  42 
E)  0.024

Question 19

Write a balanced chemical equation which corresponds to the following equilibrium constant expression.

Accepted Answer

A)  HNO2(aq)+ H2O(   )   NO2-(aq)+ H3O+(aq) 
B)  NO2-(aq)+ H3O+(aq)   HNO2(aq)+ H2O(   ) 
C)  NO2-(aq)+ H3O+(aq)   HNO2(aq) 
D)  H+(aq)+ OH-(aq)   H2O(   ) 
E)  HNO2(aq)   NO2-(aq)+ H3O+(aq) 
A)  HNO2(aq)+ H2O(   )   NO2-(aq)+ H3O+(aq) 
B)  NO2-(aq)+ H3O+(aq)   HNO2(aq)+ H2O(   ) 
C)  NO2-(aq)+ H3O+(aq)   HNO2(aq) 
D)  H+(aq)+ OH-(aq)   H2O(   ) 
E)  HNO2(aq)   NO2-(aq)+ H3O+(aq)

Question 20

At a given temperature,0.0664 mol N2O4(g)is placed in a 1.00 L flask.After reaching equilibrium,the concentration of NO2(g)is 6.1 × 10-3 M.What is Kc for the reaction below? N2O4(g)   2 NO2(g)

Accepted Answer

A)  3.7 ×10-5 
B)  1.4 ×10-4 
C)  5.9 × 10-4 
D)  9.6 × 10-2 
E)  1.8 × 103 
A)  3.7 ×10-5 
B)  1.4 ×10-4 
C)  5.9 × 10-4 
D)  9.6 × 10-2 
E)  1.8 × 103

Exam 16: Principles of Chemical Reactivity: Equilibria

What is the Kc equilibrium-constant expression for the following equilibrium? NiO(s)+ H2(g) Ni(s)+ H2O(g)

Which of the following expressions for K is correct for the reaction given below? Al3+(aq)+ 4 OH-(aq) Al(OH)4-(aq)

Given the equilibrium constants for the following reactions: 4Cu(s)+ O2(g) 2Cu2O(s),K1 4CuO(s) 2Cu2O(s)+ O2(g),K2 What is K for the system 2Cu(s)+ O2(g) 2CuO(s) Equivalent to?

What is the expression for Kc for the following equilibrium? CaSO3(s) CaO(s)+ SO2(g)

For the reaction given below,2.00 moles of A and 3.00 moles of B are placed in a 6.00-L container. A(g)+ 2B(g) C(g) At equilibrium,the concentration of A is 0.230 mol/L.What is the value of Kc?

The reaction quotient,Q,for a system is .If the equilibrium constant for the system at some temperature is ,what will happen as the reaction mixture returns to equilibrium?

Which of the following is the correct balanced equation for the equilibrium expression given below?

If the reaction quotient,Q,is equal to K in a gas phase reaction,then

Which of the following is always true for a reaction where Kc is at 25°C?

In which of the following reactions does a decrease in the volume of the reaction vessel at constant temperature favor the formation of the products?

What is the reaction quotient,Q,for the equilibrium CuCl(s) Cu+(aq)+ Cl−(aq) When 0.3746 L of M Cu+ is combined with 0.4326 L of M Cl− in the presence of an excess of CuCl(s)?

Consider the reaction A(aq) 2 B(aq)where Kc = 4.1 at 25 °C.If 0.50 M A(aq)and 1.5 M B(aq)are initially present in a 1.0 L flask at 25 °C,what change in concentrations (if any)will occur in time?

The equilibrium constant (Kc)for the decomposition of ammonium hydrogen sulfide,NH4HS(s) NH3(g)+ H2S(g),is 1.8 × 10-4 at 25 °C.If excess NH4HS(s)is allowed to equilibrate at 25 °C,what is the equilibrium concentration of NH3?

In 1913,the Haber-Bosch process was patented.The product of the Haber-Bosch process is ________.

For the equilibrium PCl5(g) PCl3(g)+ Cl2(g),Kc = 4.0 at 228°C.If pure PCl5 is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl5(g)is 0.19 M,what is the equilibrium concentration of PCl3?

At a given temperature,K = 0.024 for the equilibrium: PCl5(g) PCl3(g)+ Cl2(g) What is K for: Cl2(g)+ PCl3(g) PCl5(g)?

Write a balanced chemical equation which corresponds to the following equilibrium constant expression.

At a given temperature,0.0664 mol N2O4(g)is placed in a 1.00 L flask.After reaching equilibrium,the concentration of NO2(g)is 6.1 × 10-3 M.What is Kc for the reaction below? N2O4(g) 2 NO2(g)

Basic Concepts of Chemistry

Lets Review: The Tools of Quantitative Chemistry

Atoms, molecules, and Ions

Chemical Reactions

Stoichiometry: Quantitative Information About Chemical Reactions

Principles of Chemical Reactivity: Energy and Chemical Reactions

The Structure of Atoms

The Structure of Atoms and Periodic Trends

Bonding and Molecular Structure

Bonding and Molecular Structure Orbital Hybridization and Molecular Orbitals

Gases and Their Properties

Intermolecular Forces and Liquids

The Solid State

Solutions and Their Behavior

Chemical Kinetics: the Rates of Chemical Reactions

Principles of Chemical Reactivity: the Chemistry of Acids and Bases

Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

Principles of Chemical Reactivity: Entropy and Free Energy

Principles of Chemical Reactivity: Electron Transfer Reactions

Environmental Chemistry: Earths Environment, energy, and Sustainability

The Chemistry of the Main Group Elements

The Chemistry of the Transition Elements

Carbon: Not Just Another Element

Biochemistry

Nuclear Chemistry

Filters

What is the K_c equilibrium-constant expression for the following equilibrium? NiO(s)+ H₂(g) Ni(s)+ H₂O(g)

Which of the following expressions for K is correct for the reaction given below? Al³⁺(aq)+ 4 OH^-(aq) Al(OH)₄^-(aq)

Given the equilibrium constants for the following reactions: 4Cu(s)+ O₂(g) 2Cu₂O(s),K₁4CuO(s) 2Cu₂O(s)+ O₂(g),K₂ What is K for the system 2Cu(s)+ O₂(g) 2CuO(s) Equivalent to?

What is the expression for K_c for the following equilibrium? CaSO₃(s) CaO(s)+ SO₂(g)

For the reaction given below,2.00 moles of A and 3.00 moles of B are placed in a 6.00-L container. A(g)+ 2B(g) C(g) At equilibrium,the concentration of A is 0.230 mol/L.What is the value of K_c?

Which of the following is always true for a reaction where K_c is at 25°C?

What is the reaction quotient,Q,for the equilibrium CuCl(s) Cu⁺(aq)+ Cl−(aq) When 0.3746 L of M Cu⁺ is combined with 0.4326 L of M Cl− in the presence of an excess of CuCl(s)?

Consider the reaction A(aq) 2 B(aq)where K_c = 4.1 at 25 °C.If 0.50 M A(aq)and 1.5 M B(aq)are initially present in a 1.0 L flask at 25 °C,what change in concentrations (if any)will occur in time?

The equilibrium constant (K_c)for the decomposition of ammonium hydrogen sulfide,NH₄HS(s) NH₃(g)+ H₂S(g),is 1.8 × 10^-4 at 25 °C.If excess NH₄HS(s)is allowed to equilibrate at 25 °C,what is the equilibrium concentration of NH₃?

For the equilibrium PCl₅(g) PCl₃(g)+ Cl₂(g),K_c = 4.0 at 228°C.If pure PCl₅ is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl₅(g)is 0.19 M,what is the equilibrium concentration of PCl₃?

At a given temperature,K = 0.024 for the equilibrium: PCl₅(g) PCl₃(g)+ Cl₂(g) What is K for: Cl₂(g)+ PCl₃(g) PCl₅(g)?

At a given temperature,0.0664 mol N₂O₄(g)is placed in a 1.00 L flask.After reaching equilibrium,the concentration of NO₂(g)is 6.1 × 10^-3 M.What is K_c for the reaction below? N₂O₄(g) 2 NO₂(g)