Chapter 14.8, Problem 14.11PSP

Interpretation Introduction

Interpretation:

The pH of $\text{0}\text{.10 M }\text{}{\text{Na}}_2{\text{CO}}_{\text{3}}$ has to be calculated.

Concept Introduction:

Base ionization constant $K_b$

The equilibrium expression for the ionization of weak base $\text{B}$ will be,

  ${\text{B}}_{\text{(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{HB}}^{\text{+}}{}_{\text{(aq)}}{\text{+OH}}^{\text{-}}{}_{\text{(aq)}}$

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

Where ${\text{K}}_{\text{b}}$ is base ionization constant, $[{\text{OH}}^{-}\text{]}$ is concentration of hydroxide ion, $[{\text{HB}}^{\text{+}}\text{]}$ is concentration of conjugate acid, $[\text{B]}$ is concentration of the base.

pH definition:

The pH of a solution is defined as the negative base-10 logarithm of the hydronium ion ${\text{[H}}_{\text{3}}{\text{O}}^{+}\text{]}$ concentration.

  $\text{pH}\text{=}{\text{-log[H}}_{\text{3}}{\text{O}}^{+}\text{]}$

Relationship between pH  and pOH:

  $\text{pH + pOH = 14}$