Chapter 18, Problem 46QP

Interpretation Introduction

Interpretation:

The standard free energy change and the free energy change for the given equilibrium reaction are to be determined.

Concept introduction:

For a general chemical reaction, $\text{aA + bB }\underset{}{\overset{}{\rightleftarrows }}\text{cC+dD}$, the reaction quotient will be represented as follows:

$Q=\frac{{\text{[C]}}^{\text{c}}{\text{[D]}}^{\text{d}}}{{\text{[A]}}^{\text{a}}{\text{[B]}}^{\text{b}}}$

The standard free energy change of the reaction is the difference between the sums of the standard free energy change of the products and the standard free energy change of the reactants.

$\Delta {\text{G}}_{rxn}^{\circ }\text{=}{\displaystyle \sum \Delta {\text{G}}_{product}^{\circ }}-{\displaystyle \sum \Delta {\text{G}}_{reac\tan t}^{\circ }}$

The relation between free energy change and standard free energy change is as follows:

$\Delta G=\Delta G^{\text{o}}+\text{R}T\ln Q$

Here, $\Delta G$

is free energy change, $\Delta G^o$

is standard free energy change, $Q$ is the reaction quotient, $\text{R}$

is the gas constant, and $T$ is the temperature.