Chapter 17, Problem 17.68P

(a)

Interpretation Introduction

Interpretation:

The effect of decrease in the container volume for the given amounts of reactants and products has to be predicted.

  ${\text{H}}_{\text{2}}{\text{(g) + Cl}}_{\text{2}}\text{(g)}\rightleftharpoons \text{2HCl (g)}$

Concept Introduction:

Le Chatelier’s principle:

Le Chatelier’s principle states that the changes in the temperature, pressure, volume and concentration of the system results in the change in system to attain new equilibrium.  It is used to understand the conditions of a reaction which favours increased product formation.

Change in equilibrium due to pressure changes:

On increase in the system pressure, the equilibrium shifts towards fewer moles of gas, because, for gases,

  $\text{increase in pressure = decrease in volume}\text{.}$

On decrease in the system pressure, the equilibrium shifts towards more moles of gas, because, for gases,

  $\text{decrease in pressure = increase in volume}\text{.}$

(b)

Interpretation Introduction

Interpretation:

The effect of decrease in the container volume for the given amounts of reactants and products has to be predicted.

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

Concept Introduction:

Le Chatelier’s principle:

Le Chatelier’s principle states that the changes in the temperature, pressure, volume and concentration of the system results in the change in system to attain new equilibrium.  It is used to understand the conditions of a reaction which favours increased product formation.

Change in equilibrium due to pressure changes:

On increase in the system pressure, the equilibrium shifts towards fewer moles of gas, because, for gases,

  $\text{increase in pressure = decrease in volume}\text{.}$

On decrease in the system pressure, the equilibrium shifts towards more moles of gas, because, for gases,

  $\text{decrease in pressure = increase in volume}\text{.}$