Chapter 3, Problem 7PP

Interpretation Introduction

Interpretation:

The stronger base is to be identified using ${\text{pK}}_{\text{a}}$ values given in Table 3.1.

Concept introduction:

The strength of an acid is generally described in terms of acidity constant $\left(K_{\text{a}}\right)$ and $\text{p}{K}_{\text{a}}$ values.

A large value of $K_{\text{a}}$ indicates that the acid is strong and a small value of $K_{\text{a}}$ indicates a weak acid.

The value of ${\text{pK}}_{\text{a}}$ of a reagent can be mathematical defined as

${\text{pK}}_{\text{a}}{\text{= - log(K}}_{\text{a}}\text{) }$,

The higher is the dissolution constant, that is, the reagent can produce more ions when dissolved in water, the stronger is the acid. Thus, by the above relation, strong acids have low ${\text{pK}}_{\text{a}}$.

The stronger the acid, the weaker is its conjugate base.

Larger the value of ${\text{pK}}_{\text{a}}$ of the conjugate base, the stronger is the acid.