Chapter 6, Problem 6.48P

Interpretation Introduction

(a)

Interpretation:

The products of the proton transfer reaction shown below is to be drawn.

Concept introduction:

In a proton transfer reaction, Bronsted-Lowry base reacts with Bronsted-Lowry acid. Here, Bronsted-Lowry acid donates a proton and forms a conjugate base while Bronsted-Lowry base accepts a proton and forms a conjugate acid. The proton transfer reaction consists of a single elementary step.

Interpretation Introduction

(b)

Interpretation:

A free energy diagram for the following reaction, indicating whether it is endothermic or exothermic, is to be drawn.

Concept introduction:

When comparing two acids, the acid with the lower ${\text{pK}}_{\text{a}}$ value is the stronger acid. From the ${\text{K}}_{\text{eq}}$ values, the direction of the reaction can be found. ${\text{K}}_{\text{eq}}>1$ favors products. ${\text{K}}_{\text{eq}}<1$ favors reactants. The equilibrium constant between reactants and products is related to standard Gibbs free energy difference.

${\text{ΔG}}^{\text{0}}{}_{\text{rxn}}=\text{-RT}\text{}{\text{ln(K}}_{\text{eq}})$

A reaction tends to be spontaneous if ${\text{ΔG}}^{\text{0}}{}_{\text{rxn}}<0$. Such a reaction is exothermic because it releases free energy. A reaction tends to be nonspontaneous if ${\text{ΔG}}^{\text{0}}{}_{\text{rxn}}>0$. Such reaction is endothermic because it absorbs free energy.