Chapter 17, Problem 17.19QP

Interpretation Introduction

Interpretation:

The buffer solution of $\text{pH 3}\text{.25}$ has to be prepared from the given acid dissociation constants of diprotic acid.

Concept introduction:

• $\text{pH}\text{=}{\text{pK}}_{\text{a}}\text{+}\text{log}\frac{\text{[conjugate base]}}{\text{[acid]}}$ is Henderson–Hasselbalch equation.
• An effective buffer is the one whose $\text{pH}$ equals to ${\text{pK}}_{\text{a}}$.  Because when the concentrations of weak acid or weak base and its conjugates are same it will not be acidic or basic and maintains buffering capacity, otherwise increase in concentrations of any one leads to lose its buffering capacity.
• Buffer solution is defined as a solution that oppose changes in $\text{pH}$ while adding little amount of either an acid or a base.  In general, addition of acid or base does not affect the $\text{pH}$ in buffer solution but if it is more than amount of conjugate base or conjugate acid, then buffer loses its buffering capacity.
• If a solution has to be buffer then it should be combination of a weak acid and its conjugate base or a weak base and its conjugate acid.

To identify: the buffer solution from the given combination.