Chapter 16, Problem 16.18QP

Interpretation Introduction

Interpretation: The buffer capacities of the two of the buffer solution of different weak acid with different $\text{p}{K}_{\text{a}}$ and with same concentration of the acids and their conjugate bases are to be compared.

Concept introduction: The buffer capacity of buffer solution is calculated by the formula,

$\text{Buffer}\text{capacity}=2.303\left(\frac{K_{\text{w}}}{{\left[{\text{H}}^{+}\right]}^2}+\left[{\text{H}}^{+}\right]+\frac{C_{\text{buf}}\times K_{\text{a}}\times \left[{\text{H}}^{+}\right]}{{\left(K_{\text{a}}+\left[{\text{H}}^{+}\right]\right)}^2}\right)$

Where,

• $K_{\text{w}}$ is the dissociation constant of water that is constant.
• $\left[{\text{H}}^{+}\right]$ is the concentration of the protons produced by an acid.
• $K_{\text{a}}$ is the dissociation of weak acid.
• $C_{\text{buf}}$ is the total concentration of the weak acid and its conjugate base.

To compare: The buffer capacities of the two of the buffer solution of different weak acid with different $\text{p}{K}_{\text{a}}$ and with same concentration of the acids and their conjugate bases.