Chapter 8, Problem 19E

Interpretation Introduction

Interpretation : The relation between the pH of the buffer solution and the pK_a value of the weak acid where $[\text{Weak acid] > [ Conjugate base]}$ needs to be determined and the relation between pH and pK_a where $[\text{Weak acid] < [ Conjugate base]}$ should be discussed.

Concept Introduction :

Henderson-Hasselbalch equation is represented as follows:

  ${\text{pH = pK}}_a+\log \frac{\left[\text{conjugate base}\right]}{\left[\text{acid}\right]}$

Here, ${\text{pK}}_a$ is negative log of acid dissociation constant of an acid. $\left[\text{conjugate base}\right]$ is concentration of conjugate base and $\left[\text{acid}\right]$ is concentration of an acid.