Chapter 8, Problem 20A

Interpretation Introduction

Interpretation: The dissociation of HCl, ${\text{HNO}}_{\text{3}}$ , ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ and ${\text{HClO}}_{\text{4}}$ in water needs to be explained.

Concept Introduction: Acids are the substances which tend to give ${\text{H}}^{\text{+}}$ ions in their solution whereas bases give ${\text{OH}}^{\text{-}}$ ions.

The acid-base reaction is the reaction of acid and base to form salt and water. Here salt is formed from the cation of base and anion of acid.

Answer to Problem 20A

  $\begin{array}{l}{\text{HCl}}_{\text{(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{Cl}}_{\text{(aq)}}^{-}{\text{+ H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\\ {\text{HNO}}_{\text{3}}{}_{\text{(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{NO}}_{\text{3}}{}_{\text{(aq)}}^{-}{\text{+ H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\\ {\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}{}_{\text{(aq)}}{\text{+ 2 H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{SO }}_{\text{4(aq)}}^{2-}{\text{+ 2 H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\\ {\text{HClO}}_{\text{4}}{}_{\text{(aq)}}{\text{+ H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{ClO }}_{\text{4(aq)}}^{-}{\text{+ H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\end{array}$

Explanation of Solution

Given information: HCl, ${\text{HNO}}_{\text{3}}$ , ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ and ${\text{HClO}}_{\text{4}}$ are strong acid.

On the basis of strength of acids; they can be further classified as strong and weak acid. A strong acid can be ionized completely in its solution whereas a weak acid will ionized partially ionized in its solution. The dissociation of HCl, ${\text{HNO}}_{\text{3}}$ , ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ and ${\text{HClO}}_{\text{4}}$ can be written as:

  $\begin{array}{l}{\text{HCl}}_{\text{(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{Cl}}_{\text{(aq)}}^{-}{\text{+ H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\\ {\text{HNO}}_{\text{3}}{}_{\text{(aq)}}{\text{+H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{NO}}_{\text{3}}{}_{\text{(aq)}}^{-}{\text{+ H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\\ {\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}{}_{\text{(aq)}}{\text{+ 2 H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{SO }}_{\text{4(aq)}}^{2-}{\text{+ 2 H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\\ {\text{HClO}}_{\text{4}}{}_{\text{(aq)}}{\text{+ H}}_{\text{2}}{\text{O}}_{\text{(l)}}\stackrel{}{\to }{\text{ClO }}_{\text{4(aq)}}^{-}{\text{+ H}}_{\text{3}}{\text{O}}_{\text{(aq)}}^{+}\end{array}$

Conclusion

Strong acids ionized completely in their aqueous solutions.