Question 1

The rule or principle that describes the effect of changing reaction conditions on an equilibrium is known as ________ principle.

Accepted Answer

The answer of The rule or principle that describes the...

Question 2

When a reaction is at equilibrium,

Accepted Answer

A) all reaction stops. 
B) no more reactants are converted to products. 
C) the reaction is no longer reversible. 
D) the forward and reverse reactions occur at the same rate. 
E) the products and reactants have the same energy content.

Question 3

What is the correct form of the equilibrium constant for the reaction of hydrogen and oxygen to form water? The equation is: 
2H2(g) + O2(g) ⇌ H2O(g)

Accepted Answer

A) Kc =  
B) Kc =  
C) Kc =  
D) Kc =  
E) Kc =

Question 4

In the reaction of nitrogen gas with oxygen gas to produce nitrogen oxide, what is the effect of adding more oxygen gas to the initial reaction mixture? The reaction is shown below. 
N2(g) + O2(g) ⇌ 2NO(g)

Accepted Answer

A) The equilibrium shifts to produce more N2. 
B) The equilibrium shifts to produce more NO. 
C) The equilibrium is not affected. 
D) Extra catalyst is required to reach equilibrium. 
E) The temperature of the reaction mixture is raised.

Question 5

An example of a stress on an equilibrium is the increase of pressure in a closed system when the pressure of a reactant gas is increased from 1.0 atm to 2.0 atm.

Accepted Answer

A) True 
 B)False

Question 6

In the following gas phase reaction, what is the effect of adding more NO2 to the starting reaction mixture? 2NO2(g) ⇌ N2O₄(g)

Accepted Answer

A) It would make the reaction more endothermic. 
B) It would make the reaction more exothermic. 
C) It would slow the reaction down. 
D) It would decrease the final quantity of products. 
E) It would increase the final quantity of products.

Question 7

The equilibrium constant is the ratio of the concentrations of the reactants over the concentrations of the products.

Accepted Answer

A) True 
 B)False

Question 8

What is the correct form of the equilibrium constant for this reaction? 2H2O2 (g) ⇌ 2H2O (g) + O2 (g)

Accepted Answer

A)   
B)   
C)   
D)

Question 9

A catalyst is

Accepted Answer

A) a reactant in a chemical reaction. 
B) a product in a chemical reaction. 
C) a substance that speeds up a reaction without being consumed in the reaction. 
D) a substance that increases the energy of the products. 
E) a substance that decreases the energy of the products.

Question 10

2SO2(g) + O2(g) ⇌ 2SO₃(g) For the reaction at equilibrium, if O2 is removed, the amount of SO2 present will

Accepted Answer

A) decrease 
B) increase 
C) stay the same

Question 11

In the following gas phase reaction, Kc is much less than 1. At equilibrium, which of the following statements is true? COCl₂(g) ⇌ CO(g) + Cl₂(g)

Accepted Answer

A) The concentration of reactant is much greater than the concentration of products. 
B) The concentration of products is much greater than the concentration of reactants. 
C) The concentrations of products and reactants are approximately equal. 
D) A catalyst will increase the concentration of products formed. 
E) At equilibrium, the concentrations of reactants and products are equal.

Question 12

For the following reaction, the equilibrium constant Kc is 0.60 at a certain temperature. If the concentration of NO(g) and NOBr(g) are both 0.50 M,at equilibrium, what is the concentration of Br2(g)? 
2NO(g) + Br2(g) ⇌ 2NOBr(g)

Accepted Answer

A) 1.7 M 
B) 0.60 M 
C) 0.36 M 
D) 2.8 M 
E) 1.0 M

Question 13

The reaction for the decomposition of PCl5 to chlorine and PCl₃ is shown below. PCl5(g) ⇌ PCl₃(g) + Cl₂(g) If the equilibrium concentrations are [PCl5] = 1.0 M, [PCl₃ ] = 0.10 M, [Cl₂ ] = 0.10 M, what is the value of the equilibrium constant?

Accepted Answer

A) 1.0 × 10-2 
B) 1.0 × 10-4 
C) 10 × 10-2 
D) 1.0 × 102 
E) 2.0 × 10-2

Question 14

The equilibrium constant for a reaction does not change with temperature.

Accepted Answer

A) True 
 B)False

Question 15

Activation energy is always a large amount of energy.

Accepted Answer

A) True 
 B)False

Question 16

The value of the equilibrium constant for the combination of nitrogen and oxygen to make NO is 2 × 10-9. What does this tell you about the concentrations of materials in the equilibrium mixture?

Accepted Answer

A) The concentration of products exceeds the concentration of reactants. 
B) The concentrations of reactants and products are equal. 
C) The reactants are solids. 
D) The concentration of reactants exceeds the concentration of products. 
E) The products are solids.

Question 17

The activation energy of a chemical reaction is the energy that

Accepted Answer

A) must be removed from the mixture. 
B) must be released from the mixture. 
C) initiates the reaction. 
D) activates the catalyst. 
E) is the difference in the energies of the starting materials and products.

Question 18

The equilibrium for the reaction for the decomposition of PCl5 to chlorine and PCl₃ is 0.042. PCl5(g) ⇌ PCl₃(g)+ Cl₂(g) If the equilibrium concentrations are [PCl₃ ] = 0.010 M, [Cl₂ ] = 0.10 M, what is the value of [PCl5]?

Accepted Answer

A) 0.010 M 
B) 0.0020 M 
C) 0.042 M 
D) 0.024 M 
E) 0.0010 M

Question 19

A catalyst lowers the activation energy of a chemical reaction.

Accepted Answer

A) True 
 B)False

Question 20

The rate of any chemical reaction can be determined by observing

Accepted Answer

A) the amount of product formed in a unit of time. 
B) the ratio of product concentration to reactant concentration. 
C) the percent composition of the final product. 
D) the theoretical yield of the reaction. 
E) the number of chemical bonds broken and remade.

Exam 10: Reaction Rates and Chemical Equilibrium

The rule or principle that describes the effect of changing reaction conditions on an equilibrium is known as ________ principle.

When a reaction is at equilibrium,

What is the correct form of the equilibrium constant for the reaction of hydrogen and oxygen to form water? The equation is: 2H2(g) + O2(g) ⇌ H2O(g)

In the reaction of nitrogen gas with oxygen gas to produce nitrogen oxide, what is the effect of adding more oxygen gas to the initial reaction mixture? The reaction is shown below. N2(g) + O2(g) ⇌ 2NO(g)

An example of a stress on an equilibrium is the increase of pressure in a closed system when the pressure of a reactant gas is increased from 1.0 atm to 2.0 atm.

In the following gas phase reaction, what is the effect of adding more NO2 to the starting reaction mixture? 2NO2(g) ⇌ N2O₄(g)

The equilibrium constant is the ratio of the concentrations of the reactants over the concentrations of the products.

What is the correct form of the equilibrium constant for this reaction? 2H2O2 (g) ⇌ 2H2O (g) + O2 (g)

A catalyst is

2SO2(g) + O2(g) ⇌ 2SO₃(g) For the reaction at equilibrium, if O2 is removed, the amount of SO2 present will

In the following gas phase reaction, Kc is much less than 1. At equilibrium, which of the following statements is true? COCl₂(g) ⇌ CO(g) + Cl₂(g)

For the following reaction, the equilibrium constant Kc is 0.60 at a certain temperature. If the concentration of NO(g) and NOBr(g) are both 0.50 M,at equilibrium, what is the concentration of Br2(g) ? 2NO(g) + Br2(g) ⇌ 2NOBr(g)

The reaction for the decomposition of PCl5 to chlorine and PCl₃ is shown below. PCl5(g) ⇌ PCl₃(g) + Cl₂(g) If the equilibrium concentrations are [PCl5] = 1.0 M, [PCl₃ ] = 0.10 M, [Cl₂ ] = 0.10 M, what is the value of the equilibrium constant?

The equilibrium constant for a reaction does not change with temperature.

Activation energy is always a large amount of energy.

The value of the equilibrium constant for the combination of nitrogen and oxygen to make NO is 2 × 10-9. What does this tell you about the concentrations of materials in the equilibrium mixture?

The activation energy of a chemical reaction is the energy that

The equilibrium for the reaction for the decomposition of PCl5 to chlorine and PCl₃ is 0.042. PCl5(g) ⇌ PCl₃(g) + Cl₂(g) If the equilibrium concentrations are [PCl₃ ] = 0.010 M, [Cl₂ ] = 0.10 M, what is the value of [PCl5]?

A catalyst lowers the activation energy of a chemical reaction.

The rate of any chemical reaction can be determined by observing