Chapter 6, Problem 6A.1P

(a)

Interpretation Introduction

Interpretation: The value of ${\Delta }_{\text{r}}{G}^{\Theta }$ for the given reaction has to be calculated.

Concept introduction: The Gibbs free energy of the reaction is the key factor of the identification of the direction of spontaneity of the reaction.  For the reaction to be spontaneous, the Gibbs free energy of the reaction must be negative.

(b)

Interpretation Introduction

Interpretation: The partial pressure of $\text{IBr}\left(\text{g}\right)$ at equilibrium has to be calculated.

Concept introduction: The equilibrium constant for a reaction is abbreviated as $K$.  The value of $K$ is defined for a closed system.  The value of $K$ decides whether the equilibrium reaction will be spontaneous in forward direction or in the backward direction.

(c)

Interpretation Introduction

Interpretation: Considering the vapour pressure of iodine at $25{}^{\circ }\text{C}$, the partial pressure of $\text{IBr}\left(\text{g}\right)$ at equilibrium has to be calculated.

Concept introduction: The equilibrium constant for a reaction is abbreviated as $K$.  The value of $K$ is defined for a closed system.  The value of $K$ decides whether the equilibrium reaction will be spontaneous in forward direction or in the backward direction.