Chapter 14, Problem 14.91SP

Interpretation Introduction

Interpretation:

The values of ${\text{K}}_{\text{b}}$ and ${\text{pK}}_{\text{b}}$ of $\text{0}\text{.0010}\text{M}$ solution of quinine containing a $\text{pH}$ of $9.75$ has to be determined.

Concept Introduction:

Consider a reaction of weak base,

${\text{B+H}}_{\text{2}}\text{O}\stackrel{{\text{K}}_{\text{b}}}{\rightleftharpoons }{\text{BH}}^{\text{+}}{\text{+OH}}^{\text{-}}$

The base dissociation constant ${\text{K}}_{\text{b}}$ can be given as,

${\text{K}}_{\text{b}}\text{=}\frac{\left[{\text{BH}}^{\text{+}}\right]\left[{\text{OH}}^{\text{-}}\right]}{\left[\text{B}\right]}$

Where ${\text{K}}_{\text{b}}$ is called as base dissociation constant.

The ${\text{pK}}_{\text{b}}$ can be calculated as given below.

${\text{pK}}_{\text{b}}\text{= -log}\left({\text{K}}_{\text{b}}\right)$