Chapter 4, Problem 4I.2AST

Interpretation Introduction

Interpretation:

The formation of hydrogen fluoride is spontaneous or not has to be given.

Concept Introduction:

The entropy change of the surroundings due to a process taking place at constant pressure and temperature is equal to the change in enthalpy of the system at the temperature.

  $\text{ΔS=}\frac{\text{-}\text{ΔH}}{\text{T}}$

Where $\text{ΔH}$ is the change in enthalpy of the system.

T is the temperature in Kelvin.

The total change in entropy is given by,

  ${\text{ΔS}}_{\text{total}}{\text{=ΔS}}^{\text{0}}{\text{+ΔS}}_{\text{surr}}$

Where ${\text{ΔS}}^{\text{0}}$ is standard entropy.

${\text{ΔS}}_{\text{surr}}$ is entropy change in surroundings.

The spontaneity of the process can be determined by the entropy values.

• If ${\text{ΔS}}_{\text{total}}$ is positive the process is spontaneous.
• If ${\text{ΔS}}_{\text{total}}$ is negative the reverse process is spontaneous.
• If ${\text{ΔS}}_{\text{total}}$ is zero the process is has no tendency to proceed.