Chapter 12, Problem 12.25P

Interpretation Introduction

Interpretation:

The qualitative phase diagram for ethylene is to be drawn. Also, whether ${\text{C}}_2{\text{H}}_4\left(s\right)$ is more or less dense than ${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}\left(l\right)$ 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 phase melts it is converted into the 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:

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