Chapter 18, Problem 2QP

Interpretation Introduction

Interpretation:

The spontaneous and non-spontaneous processes among the given processes are to be determined.

Concept introduction:

$\Delta G^{\text{o}}$ is the actual free energy. It is a thermodynamic function and is also known as Gibb’s free energy.

Gibbs free energy is defined as the energy that can be used to get work done. The abbreviation for Gibbs Free Energy is $\Delta G$.

The standard Gibbs Free Energy, abbreviated as $\Delta G^o$, is defined as the change in free energy that is accompanied by the formation of product in their standard state from reactants in their standard state. 

An equilibrium process is the state at which the rate of the backward reaction is equal to the rate of the forward reaction.

$\Delta \text{G}\text{<}\text{0}$ (negative), the reaction is spontaneous.

$\Delta \text{G}>\text{0}$ (positive), the reaction is non-spontaneous.

$\Delta \text{G}=\text{0}$ (zero), the system is at equilibrium.

The Gibbs free energy change is calculated by using the expression as:

$\Delta G=\Delta H-T\Delta S$

Here, $\Delta G$ is Gibbs free energy change, $\Delta H$ is the enthalpy change, $T$ is the temperature, and $\Delta S$ is the entropy change.