Chapter 8, Problem 54P

Interpretation Introduction

Interpretation:

It is to be shown that the pH of buffer solution is equal to the $\text{p}{K}_{\text{a}}$ of the weak acid if the concentration of weak acid and conjugate base is same.

Concept Introduction:

The pH of buffer can be calculated using the Henderson-Hasselbalch equation as follows:

$\text{pH}=\text{p}{K}_{\text{a}}+\log \frac{\left[{\text{A}}^{-}\right]}{\left[\text{HA}\right]}$

Here, pH is negative log of hydrogen ion, $\text{p}{K}_{\text{a}}$ is negative log of acid dissociation constant, $\left[{\text{A}}^{-}\right]$ is concentration of conjugate base and $\left[\text{HA}\right]$ is concentration of acid.