Chapter 18, Problem 18.93SP

Interpretation Introduction

Interpretation:

The standard state of the substance should be described.

Concept introduction:

The standard entropy change $\left(\Delta S°\right)$ for reaction can be defined as a difference between standard molar entropies of all products and reactants. The general expression for standard entropy change for reaction is as follows:

$\Delta S°=S°\left(\text{products}\right)-S°\left(\text{reactants}\right)$

The unit of $\Delta S°$ is $\text{J/K}$ and $S$ is $\text{J/K}\cdot \text{mol}$.