Chapter 21, Problem 47PS

Interpretation Introduction

Interpretation:

To calculate the enthalpy and free energy change for the given reaction.Check whether this reaction is exothermic or endothermic and is the reaction is product or reactant favoured at eqauilibrium.

Concept introduction:

The Gibbs free energy or the free energy change is a thermodynamic quantity represented by $\Delta G^{\circ }$. The expression for the free energy change is:

${\text{Δ}}_{\text{r}}{G}^{\text{°}}=\sum n{\Delta }_f{G}^{\text{°}}\left(\text{products}\right)-\sum n{\Delta }_f{G}^{\text{°}}\left(\text{reactants}\right)$

The enthalpy change is expressed by the formula,

${\text{Δ}}_{\text{r}}{H}^{\text{°}}=\sum n{\Delta }_f{H}^{\text{°}}\left(\text{products}\right)-\sum n{\Delta }_f{H}^{\text{°}}\left(\text{reactants}\right)$

If the value of enthalpy change is negative, the reaction is exothermic.

If the value of free energy change is negative, then the reaction is product-favored at equilibrium.