Chapter 16, Problem 16.125CHP

(a)

Interpretation Introduction

Interpretation:

The following equation has to be derived.

$\ln K=\frac{-\Delta H°}{R}\left(\frac{1}{T}\right)+\frac{\Delta S°}{R}$

Concept Introduction:

Standard free energy change of a reaction is related to equilibrium constant of a reaction as,

$\Delta G°=-\text{ RT ln K}$

Where,

$\begin{array}{l}\Delta G°=\text{ standard free energy change}\\ R=\text{ Universal gas constant}\\ \text{T}=\text{ Temperature}\\ \text{K}\text{= equilibrium constant of a reaction}\end{array}$

Standard free energy change of a reaction is also related to standard enthalpy change and entropy change as follows,

$\Delta G°=\Delta H°-T\Delta S°$

(b)

Interpretation Introduction

Interpretation:

The usage of following equation in determining experimental values of $\Delta H°$ and $\Delta S°$ has to be explained.

$\ln K=\frac{-\Delta H°}{R}\left(\frac{1}{T}\right)+\frac{\Delta S°}{R}$

Concept Introduction:

Standard free energy change of a reaction is related to equilibrium constant of a reaction as,

$\Delta G°=-\text{ RT ln K}$

Where,

$\begin{array}{l}\Delta G°=\text{ standard free energy change}\\ R=\text{ Universal gas constant}\\ \text{T}=\text{ Temperature}\\ \text{K}\text{= equilibrium constant of a reaction}\end{array}$

Standard free energy change of a reaction is also related to standard enthalpy change and entropy change as follows,

$\Delta G°=\Delta H°-T\Delta S°$

(c)

Interpretation Introduction

Interpretation:

Using the following equation sign of $\Delta H°$ for a reaction whose equilibrium constant increases with increase in temperature has to be predicted.

The reaction is whether exothermic or endothermic has to be ascertained.

The reliability of the prediction with Le Chatelier’s principle has to be ascertained.

$\ln K=\frac{-\Delta H°}{R}\left(\frac{1}{T}\right)+\frac{\Delta S°}{R}$

Concept Introduction:

Le Chatelier’s principle states that if a system undergoes change in temperature or pressure or concentration of its component, the equilibrium of the system will shift in a direction such a way that the system tend to counteract the effects caused by the change in temperature or pressure or concentration of its component.

Sign of $\Delta H°$ is positive for endothermic reaction and negative for exothermic reaction.