Chapter U6, Problem 2RE

Interpretation Introduction

(a)

Interpretation:

The equilibrium constant equation for the reversible reaction of chlorine gas to form liquid chlorine needs to be determined.

Concept introduction:

An equilibrium reaction is represented as follows:

$A+B\rightleftharpoons AB$

For the above reaction, the change in concentration of A and B is equal to that of AB.

For the above reaction, equilibrium constant can be represented as follows:

$K=\frac{\left[AB\right]}{\left[A\right]\left[B\right]}$

Here, K is equilibrium constant.

Explanation of Solution

The reaction showing chlorine gas to form liquid chlorine is represented as follows:

${\text{Cl}}_2\left(g\right)\rightleftharpoons {\text{Cl}}_2\left(l\right)$

Here, 1 mol of chlorine gas gets converted into 1 mol of liquid chlorine.

The equilibrium constant does not involve species in pure liquid and solid form thus, species in aqueous solution and in gas state can only participate in the equilibrium expression.

The equilibrium constant equation for the above reaction will be:

$K=\frac{1}{\left[{\text{Cl}}_{\text{2}}\left(g\right)\right]}$

Interpretation Introduction

(b)

Interpretation:

The equilibrium constant equation for the reversible reaction of nitrogen dioxide to form dinitrogen tetraoxide needs to be written.

Concept introduction:

An equilibrium reaction is represented as follows:

$A+B\rightleftharpoons AB$

For the above reaction, the change in concentration of A and B is equal to that of AB.

For the above reaction, equilibrium constant can be represented as follows:

$K=\frac{\left[AB\right]}{\left[A\right]\left[B\right]}$

Here, K is equilibrium constant.

Explanation of Solution

The reaction showing nitrogen dioxide to form dinitrogen tetraoxide is represented as follows:

${\text{2NO}}_2\left(g\right)\rightleftharpoons {\text{N}}_{\text{2}}{\text{O}}_{\text{4}}\left(g\right)$

Here 2 moles of nitrogen dioxide form 1 dinitrogen tetraoxide.

The equilibrium constant equation can be represented as follows:

$K=\frac{\left[{\text{N}}_{\text{2}}{\text{O}}_{\text{4}}\left(g\right)\right]}{{\left[{\text{NO}}_2\left(g\right)\right]}^2}$

(c)

Interpretation Introduction

Interpretation:

The equilibrium constant equation for the reversible reaction of precipitation of silver chloride from aqueous solution needs to be determined.

Concept introduction:

An equilibrium reaction is represented as follows:

$A+B\rightleftharpoons AB$

For the above reaction, the change in concentration of A and B is equal to that of AB.

For the above reaction, equilibrium constant can be represented as follows:

$K=\frac{\left[AB\right]}{\left[A\right]\left[B\right]}$

Here, K is equilibrium constant.

Explanation of Solution

The silver chloride is formed when silver nitrate solution which is colorless is added to colorless aqueous solution of sodium chloride, silver chloride is formed which is a white precipitate.

The reaction showing precipitation of silver chloride is represented as follows:

${\text{AgNO}}_{\text{3}}\left(aq\right)+\text{NaCl}\left(aq\right)\rightleftharpoons \text{AgCl}\left(s\right)+{\text{NaNO}}_{\text{3}}\left(aq\right)$

The equilibrium constant does not involve species in pure liquid and solid form thus, species in aqueous solution and in gas state can only participate in the equilibrium expression.

The equilibrium constant equation for the above reaction can be represented as follows:

$K=\frac{\left[{\text{NaNO}}_{\text{3}}\left(aq\right)\right]}{\left[{\text{AgNO}}_{\text{3}}\left(aq\right)\right]\left[\text{NaCl}\left(aq\right)\right]}$

(d)

Interpretation Introduction

Interpretation:

The equilibrium constant equation for the reversible reaction of evaporation of water needs to be written.

Concept introduction:

An equilibrium reaction is represented as follows:

$A+B\rightleftharpoons AB$

For the above reaction, the change in concentration of A and B is equal to that of AB.

For the above reaction, equilibrium constant can be represented as follows:

$K=\frac{\left[AB\right]}{\left[A\right]\left[B\right]}$

Here, K is equilibrium constant.

Explanation of Solution

Liquid water can evaporate to form steam or water vapor. The reaction showing evaporation of water is as follows:

${\text{H}}_{\text{2}}\text{O}\left(l\right)\rightleftharpoons {\text{H}}_{\text{2}}\text{O}\left(g\right)$

Here, only state of water changes from liquid to gas.

The equilibrium constant does not involve species in pure liquid and solid form thus, species in aqueous solution and in gas state can only participate in the equilibrium expression.

The equilibrium constant equation for the above reaction can be represented as follows:

$K=\left[{\text{H}}_{\text{2}}\text{O}\left(g\right)\right]$