Question 1

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 2

For the reaction of carbon with carbon dioxide to make carbon monoxide, one set of conditions produced a Kc = 1.2 × 10-1. At equilibrium at a certain temperature, the concentration of product was 0.60 M. What was the concentration of carbon dioxide at that temperature? 
C(s) + CO₂(g) ⇌ 2CO(g)

Accepted Answer

A)  3.0 M 
B)  0.60 M 
C)  0.36 M 
D)  3.33 M 
E)  5.0 M

Question 3

In an exothermic reaction, heat can be considered a __________.

Accepted Answer

A)  reactant 
B)  product 
C)  rate 
D)  catalyst 
E)  determinant

Question 4

For the following reaction, the equilibrium constant Kc is 2.0 at a certain temperature. If the concentration of both products is 0.10 M at equilibrium, what is the concentration of the starting material, NOBr?
 2NOBr(g) ⇌ 2NO(g) + Br₂(g)

Accepted Answer

A)  5 × 10-4 M 
B)  2.2 × 10-4 M 
C)  5 × 10-2 M 
D)  2.2 × 10-2 M 
E)  2.2 M

Question 5

For the reaction of carbon with carbon dioxide to make carbon monoxide, the reaction is as follows. C(s) + CO₂(g) ⇌ 2CO(g)
Adding additional C(s) to the reaction container will cause __________ to occur.

Accepted Answer

A)  the formation of more CO 
B)  the formation of more CO₂ 
C)  a decrease in the amount of CO 
D)  B and C 
E)  no change in the amounts of CO and CO₂

Question 6

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 7

When you open a bottle of a soft drink and leave it open, the drink eventually goes flat. This happens because the equilibrium between carbonic acid and carbon dioxide shifts to produce

Accepted Answer

A)  more carbonic acid. 
B)  more water. 
C)  more oxygen. 
D)  more carbon dioxide. 
E)  more hydrogen ions.

Question 8

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 9

A chemical reaction has reached equilibrium when

Accepted Answer

A)  the concentrations of reactants and products are equal. 
B)  all reactants have been converted to products. 
C)  all products have been removed from the reaction mixture. 
D)  the catalyst has been used up. 
E)  the rate of the forward reaction equals the rate of the reverse reaction.

Question 10

What is the correct form of the equilibrium constant for this reaction? 2H?O?(g) ? 2 H?O (g) + O?(g)

Accepted Answer

A)  $\frac { \left[ \mathrm { H } _ { 2 } \bigcirc \right] } { \left[ \mathrm { H } _ { 2 } \bigcirc \frac { 1 } { 2 } \right] }$ 
B)  $\frac { \left[ \mathrm { O } _ { 2 } \right] \left[ \mathrm { H } _ { 2 } \mathrm { O } \right] ^ { 2 } } { \left[ \mathrm { H } _ { 2 } \mathrm { O } _ { 2 } \right] ^ { 2 } }$ 
C)  $\frac { \left[ \mathrm { H } _ { 2 } \bigcirc \right] ^ { 2 } } { \left[ \mathrm { H } _ { 2 } \bigcirc 2 \right] }$ 
D)  $\frac { \left[ \mathrm { H } _ { 2 } \bigcirc \right] \left[ \mathrm { O } _ { 2 } \right] } { \left[ \mathrm { H } _ { 2 } \mathrm { O } _ { 2 } \right] }$

Question 11

A heterogeneous equilibrium is one in which the reactants and products are found in two or more physical states.

Accepted Answer

A) True 
 B)False

Exam 9: Reaction Rates and Chemical Equilibrium

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]?

For the reaction of carbon with carbon dioxide to make carbon monoxide, one set of conditions produced a K_c = 1.2 × 10^-1. At equilibrium at a certain temperature, the concentration of product was 0.60 M. What was the concentration of carbon dioxide at that temperature? C(s) + CO₂(g) ⇌ 2CO(g)

In an exothermic reaction, heat can be considered a __________.

For the following reaction, the equilibrium constant Kc is 2.0 at a certain temperature. If the concentration of both products is 0.10 M at equilibrium, what is the concentration of the starting material, NOBr? 2NOBr(g) ⇌ 2NO(g) + Br₂(g)

For the reaction of carbon with carbon dioxide to make carbon monoxide, the reaction is as follows. C(s) + CO₂(g) ⇌ 2CO(g) Adding additional C(s) to the reaction container will cause __________ to occur.

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)

When you open a bottle of a soft drink and leave it open, the drink eventually goes flat. This happens because the equilibrium between carbonic acid and carbon dioxide shifts to produce

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

A chemical reaction has reached equilibrium when

What is the correct form of the equilibrium constant for this reaction? 2H?O?(g) ? 2 H?O (g) + O?(g)

A heterogeneous equilibrium is one in which the reactants and products are found in two or more physical states.

Exam 9: Reaction Rates and Chemical Equilibrium

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]?

For the reaction of carbon with carbon dioxide to make carbon monoxide, one set of conditions produced a Kc = 1.2 × 10-1. At equilibrium at a certain temperature, the concentration of product was 0.60 M. What was the concentration of carbon dioxide at that temperature? C(s) + CO₂(g) ⇌ 2CO(g)

In an exothermic reaction, heat can be considered a __________.

For the following reaction, the equilibrium constant Kc is 2.0 at a certain temperature. If the concentration of both products is 0.10 M at equilibrium, what is the concentration of the starting material, NOBr? 2NOBr(g) ⇌ 2NO(g) + Br₂(g)

For the reaction of carbon with carbon dioxide to make carbon monoxide, the reaction is as follows. C(s) + CO₂(g) ⇌ 2CO(g) Adding additional C(s) to the reaction container will cause __________ to occur.

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)

When you open a bottle of a soft drink and leave it open, the drink eventually goes flat. This happens because the equilibrium between carbonic acid and carbon dioxide shifts to produce

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

A chemical reaction has reached equilibrium when

What is the correct form of the equilibrium constant for this reaction? 2H?O?(g) ? 2 H?O (g) + O?(g)

A heterogeneous equilibrium is one in which the reactants and products are found in two or more physical states.

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]?

For the reaction of carbon with carbon dioxide to make carbon monoxide, one set of conditions produced a K_c = 1.2 × 10^-1. At equilibrium at a certain temperature, the concentration of product was 0.60 M. What was the concentration of carbon dioxide at that temperature? C(s) + CO₂(g) ⇌ 2CO(g)