Chapter 7, Problem 16DQ

Interpretation Introduction

Interpretation: The reason of pH = 7 for water at 25 °C needs to be explained.

Concept Introduction: An acid is the substance that gives H+ or ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ ions in its aqueous solution. An acid is ionized and gives the respective ions.

  ${\text{HA}}_{\text{(aq)}}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l) }}\stackrel{}{\to }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{\text{(aq)}}{\text{+A}}^{\text{-}}{}_{\text{(aq)}}$

On the contrary, a base ionized to given ${\text{OH}}^{\text{-}}$ ions in the solution.

  ${\text{BOH}}_{\text{(aq)}}\rightleftharpoons {\text{B}}^{\text{+}}{}_{\text{(aq)}}{\text{+ OH}}^{\text{-}}{}_{\text{(aq)}}$