Chapter 22.4, Problem 5P

Interpretation Introduction

Interpretation:

The ${\text{CH}}_{\text{3}}{\text{NH}}_3{}^{+}/{\text{CH}}_{\text{3}}{\text{NH}}_{\text{2}}$ ratio in water buffered at $\text{pH}\text{7}$ is to be calculated.

Concept introduction:

At particular $\text{pH}$, the Henderson-Hasselbalch equation can be used to determine the ratio of concentrations of a base and its conjugate acid. The ratio of the concentration of a base and its conjugate acid is calculated by the formula given below.

$\frac{\left[\text{conjugate}\text{acid}\right]}{\left[\text{base}\right]}={10}^{\left(\text{pH}-\text{p}{K}_{\text{b}}\right)}$