Chapter 4, Problem 4.1P

(a)

Interpretation Introduction

Interpretation:

Whether an increase in temperature be expected to make monoclinic sulfur more stable than rhombic sulfur has to be decided.

Concept Introduction:

The variation of Gibbs energy with temperature:

Gibbs energy depends on temperature and pressure. It can be represented as

$d{G}_m=V_{m}dp-S_{m}dT$

Where,

$G_m=$ Molar Gibbs free energy

$V_m=$ Molar volume

$S_m=$ Molar entropy

At constant pressure, $dp=0$

Then the equation becomes $\boxed{d{G}_m=-S_{m}dT}$

(b)

Interpretation Introduction

Interpretation:

The transition temperature at $1bar$ has to be calculated.

Concept Introduction:

The variation of Gibbs energy with temperature:

Gibbs energy depends on temperature and pressure.  It can be represented as

$d{G}_m=V_{m}dp-S_{m}dT$

Where,

$G_m=$ Molar Gibbs free energy

$V_m=$ Molar volume

$S_m=$ Molar entropy

At constant pressure, $dp=0$

Then the equation becomes $\boxed{d{G}_m=-S_{m}dT}$