Chapter 15, Problem 15.134CHP

Interpretation Introduction

Interpretation:

The volume in millilitres of sodium acetate and acetic acid that should be mixed together to obtain $\text{20}\text{.0}\text{ml}$ of solution with $\text{pH}\text{4}\text{.85}$ has to be given.

Concept Introduction:

Henderson-Hasselbalch equation:

Henderson- Hasselbalch equation is rearranged form of acid dissociation expression.

For base:

Consider a basic reaction:

${\text{BH}}^{\text{+}}\stackrel{{\text{K}}_{\text{a}}{\text{=K}}_{\text{w}}{\text{/K}}_{\text{b}}}{\rightleftharpoons }{\text{B+H}}^{\text{+}}$

The Henderson- Hasselbalch equation for a basic reaction can be given as,

${\text{pH=pK}}_{\text{a}}\text{+log}\frac{\left[\text{B}\right]}{\left[{\text{BH}}^{\text{+}}\right]}$

Where, ${\text{pK}}_{\text{a}}$= acid dissociation constant for weak acid ${\text{BH}}^{\text{+}}$