Chapter 3, Problem 3.20P

Interpretation Introduction

Interpretation:

The following expressions: $f_{\text{A}}=\frac{1}{1+{10}^{-\text{Δ}}}$ and $f_{\text{AH}}=\frac{1}{1+{10}^{\text{Δ}}}$ are to be derived.

Concept introduction:

The expression for dissociated fraction and undissociated fraction of an acid in a solution are given as shown below.

$f_{\text{A}}=\frac{{10}^{-\text{p}{K}_{\text{a}}}}{{10}^{-\text{p}{K}_{\text{a}}}+{10}^{-\text{pH}}}$

$f_{\text{AH}}=\frac{{10}^{-\text{pH}}}{{10}^{-\text{p}{K}_{\text{a}}}+{10}^{-\text{pH}}}$

Where,

• $f_{\text{A}}$ represents the dissociated fraction.

• $f_{\text{AH}}$ represents the undissociated fraction.