Chapter U6.6, Problem 7E

(a)

Interpretation Introduction

Interpretation: Two things to be done to change the concentration of the products of the following reaction.

  $2{\text{NO}}_{\text{2}}(g)\rightleftharpoons {\text{N}}_{\text{2}}{\text{O}}_{\text{4}}(g)$

Concept Introduction : According to Le Chatelier’s principle, when the conditions of an equilibrium mixture are modified, the system responds in such a way to reduce the effect of the change. This principle allows us to predict qualitatively hoe the system responds to changes in concentration, pressure or temperature.

Answer to Problem 7E

Two things to be done to change the concentration of the products are increase and decreasing concentration of ${\text{NO}}_{\text{2}}$ .

Explanation of Solution

If one of the products is added more to the equilibrium mixture of starting substance and product, the rate of reverse reaction will increase.

Second change is to raise or lower the temperature of solutions, which also changes the composition of equilibrium mixture of starting substances and products.

So, for the reaction, $2{\text{NO}}_{\text{2}}(g)\rightleftharpoons {\text{N}}_{\text{2}}{\text{O}}_{\text{4}}(g)$

1. Addition of ${\text{NO}}_{\text{2}}$increases the forward reaction and the concentration of product will all increase.
2. Decreasing reactant concentration will decrease rate of forward reaction and concentration of product will change.

(b)

Interpretation Introduction

Interpretation: Two things to be done to change the concentration of one of the products of the following reaction.

  $\text{HF}\text{(}aq\text{)}\rightleftharpoons {\text{H}}^{+}(aq)+{\text{F}}^{-}(aq)$

Concept Introduction : According to Le Chatelier’s principle, when the conditions of an equilibrium mixture are modified, the system responds in such a way to reduce the effect of the change. This principle allows us to predict qualitatively hoe the system responds to changes in concentration, pressure or temperature.

Answer to Problem 7E

Two things to be done to change the concentration of one of the products are addition of HF and addition of acid ${\text{H}}^{+}$ .

Explanation of Solution

If one of the products is added more to the equilibrium mixture of starting substance and product, the rate of reverse reaction will increase.

Second change is to raise or lower the temperature of solutions, which also changes the composition of equilibrium mixture of starting substances and products.

So, for the reaction,$\text{HF}\text{(}aq\text{)}\rightleftharpoons {\text{H}}^{+}(aq)+{\text{F}}^{-}(aq)$

1. Addition of $\text{HF}$increases the forward reaction and the concentration of product will all increase.
2. Addition of acid in solution will increase rate of backward reaction and concentration of ${\text{F}}^{-}$will decrease.

(c)

Interpretation Introduction

Interpretation: Two things to be done to change the concentration of one of the products of the following reaction.

  ${\text{CaCO}}_{\text{3}}(s)\rightleftharpoons \text{CaO}\text{(}s\text{)}\text{+}{\text{CO}}_2(g)$

Concept Introduction : According to Le Chatelier’s principle, when the conditions of an equilibrium mixture are modified, the system responds in such a way to reduce the effect of the change. This principle allows us to predict qualitatively hoe the system responds to changes in concentration, pressure or temperature.

Answer to Problem 7E

Two things to be done to change the concentration of one of the products are addition of ${\text{PbCl}}_2$ and temperature change.

Explanation of Solution

If one of the products is added more to the equilibrium mixture of starting substance and product, the rate of reverse reaction will increase.

Second change is to raise or lower the temperature of solutions, which also changes the composition of equilibrium mixture of starting substances and products.

So, for the reaction, ${\text{PbCl}}_{\text{2}}(s)\rightleftharpoons {\text{Pb}}^{2+}(aq)+2{\text{Cl}}^{-}(aq)$ ,

1. Addition of ${\text{PbCl}}_2$increases the forward reaction and the concentration of product will all increase.
2. Decreasing reactant concentration will decrease rate of forward reaction and concentration of product will change.
3. Temperature change.

(d)

Interpretation Introduction

Interpretation: Two things to be done to change the concentration of one of the products of the following reaction.

  ${\text{CaCO}}_{\text{3}}(s)\rightleftharpoons \text{CaO}\text{(}s\text{)}\text{+}{\text{CO}}_2(g)$

Concept Introduction: According to Le Chatelier’s principle, when the conditions of an equilibrium mixture are modified, the system responds in such a way to reduce the effect of the change. This principle allows us to predict qualitatively hoe the system responds to changes in concentration, pressure or temperature.

Answer to Problem 7E

Two things to be done to change the concentration of one of the products are addition of ${\text{CaCO}}_3$ and temperature change.

Explanation of Solution

If one of the products is added more to the equilibrium mixture of starting substance and product, the rate of reverse reaction will increase.

Second change is to raise or lower the temperature of solutions, which also changes the composition of equilibrium mixture of starting substances and products.

So, for the reaction, ${\text{CaCO}}_{\text{3}}(s)\rightleftharpoons \text{CaO}\text{(}s\text{)}\text{+}{\text{CO}}_2(g)$ ,

1. Addition of ${\text{CaCO}}_3$increases the forward reaction and the concentration of product will all increase.
2. Decreasing reactant concentration will decrease rate of forward reaction and concentration of product will change.
3. Temperature change.