Chapter 12, Problem 12.27P

(a)

Interpretation Introduction

Interpretation:

A set of conditions required for the sublimation of the rhombic form of solid sulfur is to be determined.

Concept introduction:

The phase diagram is a combination of liquid-gas, solid-liquid, and solid-gas curves and determines the effect of temperature and pressure on the phase of a substance.

When a solid melts, it is converted into a liquid phase and when a liquid freeze it changes to a solid phase. The phase changes can be expressed as follows:

$\text{Solid}\underset{\text{Freezing}}{\overset{\text{Melting}}{\rightleftarrows }}\text{Liquid}$

When a liquid is vaporized it changes into the gaseous phase and when a gas condenses it converts to the liquid phase. The phase changes can be expressed as follows:

$\text{Liquid}\underset{\text{Condensation}}{\overset{\text{Vaporization}}{\rightleftarrows }}\text{Gas}$

When solid is sublimed it changes directly to the gas phase and when gas is deposited it converts directly to the solid phase. The phase changes can be expressed as follows:

$\text{Gas}\underset{\text{Sublimation}}{\overset{\text{Deposition}}{\rightleftarrows }}\text{Solid}$

(b)

Interpretation Introduction

Interpretation:

The phase changes that a sample of sulfur undergoes at $1\text{ atm}$ when it is heated from $90°\text{C}$ to $450°\mathrm{C}$ is to be described.

Concept introduction:

The phase diagram is a combination of liquid-gas, solid-liquid, and solid-gas curves and determines the effect of temperature and pressure on the phase of a substance.

When a solid melts, it is converted into a liquid phase and when a liquid freeze it changes to a solid phase. The phase changes can be expressed as follows:

$\text{Solid}\underset{\text{Freezing}}{\overset{\text{Melting}}{\rightleftarrows }}\text{Liquid}$

When a liquid is vaporized it changes into the gaseous phase and when a gas condenses it converts to the liquid phase. The phase changes can be expressed as follows:

$\text{Liquid}\underset{\text{Condensation}}{\overset{\text{Vaporization}}{\rightleftarrows }}\text{Gas}$

When solid is sublimed it changes directly to the gas phase and when gas is deposited it converts directly to the solid phase. The phase changes can be expressed as follows:

$\text{Gas}\underset{\text{Sublimation}}{\overset{\text{Deposition}}{\rightleftarrows }}\text{Solid}$