Chapter 15, Problem 98A

Interpretation Introduction

Interpretation:

This is to be explained how exothermic reaction changes the entropy of the surroundings.

Concept introduction:

The free energy change ${\text{(ΔG}}_{\text{system}}\text{)}$ is the difference between the system’s change in enthalpy ${\text{(ΔH}}_{\text{system}}\text{)}$ and the product of the Kelvin temperature and the change in entropy ${\text{(TΔS}}_{\text{system}}\text{)}$.

Answer to Problem 98A

Enthalpy change $\text{(ΔG)}$ for such reaction will decrease.

Explanation of Solution

Simple equation for the entropy change of the surrounding is

${\text{ΔS}}_{\text{surrounding}}=-\frac{\text{ΔH}}{\text{T}}$

$\text{ΔH}$ is he enthalpy change and T is the temperature. Here $\text{ΔH}$ is negative because the reaction is an exothermic reaction.

Since, exothermic reaction gives away heat to the surrounding. Therefore, changing the entropy of surrounding.

Since,

$\text{ΔG}=\text{ΔH}-\text{TΔS}$

As exothermic reaction increases $\text{ΔH}$ will results in increasing the value of $\text{ΔG}$.