Chapter 15, Problem 15.98QE

Interpretation Introduction

Interpretation:

The manner the value of $\text{pH}$ of $0.05M\text{ HCOOH}$ and $0.050M$ phenol will be calculated has to be explained.

Concept Introduction:

For a mixture of the acids or bases, the $\text{pH}$ determination involves consideration of only predominant or strong acidic species.

The dissociation of general acid $\left(\text{HA}\right)$ as follows:

  $\text{HA}\left(\text{aq}\right)\rightleftharpoons {\text{H}}^{+}\left(\text{aq}\right)+{\text{A}}^{-}\left(\text{aq}\right)$

The expression for acid dissociation constant $\left(K_{\text{a}}\right)$ is given as,

  $K_{\text{a}}=\frac{\left[{\text{H}}^{+}\right]\left[{\text{A}}^{-}\right]}{\left[\text{HA}\right]}$

Here,

$\left[{\text{H}}^{+}\right]$ is the concentration of ${\text{H}}^{+}$ ions.

$\left[{\text{A}}^{-}\right]$ is the concentration of ${\text{A}}^{-}$ ions.

$\left[\text{HA}\right]$ is the concentration of $\text{HA}$.