Chapter 16, Problem 16.120CHP

(a)

Interpretation Introduction

Interpretation:

$\Delta S{°}_f$ for benzene has to be calculated

Concept Introduction:

$\Delta S{°}_f$ of a substance refers to entropy of formation of product.  It is the measure of entropy change when one mole of product is formed from reactants.

It is calculated as,

$\Delta S{°}_f={\displaystyle \sum _{}^{}S°(products)-}{\displaystyle \sum _{}^{}S°(reac\tan ts)}$

Where,

$\begin{array}{l}S°(products)=\text{ standard molar entropy of products}\\ \text{S}°\text{(reactants)}\text{= standard molar entropy of reactants}\end{array}$

(b)

Interpretation Introduction

Interpretation:

$\Delta S{°}_f$ for $CaS{O}_4$ has to be calculated

Concept Introduction:

$\Delta S{°}_f$ of a substance refers to entropy of formation of product.  It is the measure of entropy change when one mole of product is formed from reactants.

It is calculated as,

$\Delta S{°}_f={\displaystyle \sum _{}^{}S°(products)-}{\displaystyle \sum _{}^{}S°(reac\tan ts)}$

Where,

$\begin{array}{l}S°(products)=\text{ standard molar entropy of products}\\ \text{S}°\text{(reactants)}\text{= standard molar entropy of reactants}\end{array}$

(c)

Interpretation Introduction

Interpretation:

$\Delta S{°}_f$ for ethanol has to be calculated

Concept Introduction:

$\Delta S{°}_f$ of a substance refers to entropy of formation of product.  It is the measure of entropy change when one mole of product is formed from reactants.

It is calculated as,

$\Delta S{°}_f={\displaystyle \sum _{}^{}S°(products)-}{\displaystyle \sum _{}^{}S°(reac\tan ts)}$

Where,

$\begin{array}{l}S°(products)=\text{ standard molar entropy of products}\\ \text{S}°\text{(reactants)}\text{= standard molar entropy of reactants}\end{array}$