Write the dissociation reaction and the corresponding \(K_{\mathrm{a}}\) equilibrium expression for each of the following acids in water. a. \(\mathrm{HCN}\) b. \(\mathrm{HOC}_{6} \mathrm{H}_{5}\) c. \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3}^{+}\)

The dissociation reactions and corresponding Ka expressions for the given acids are: a. HCN: Reaction: \[ \mathrm{HCN} + \mathrm{H}_2 \mathrm{O} \rightleftharpoons \mathrm{H_3 O^+} + \mathrm{CN^-} \] Ka Expression: \[ K_{\mathrm{a}} = \frac{[\mathrm{H_3 O^+}][\mathrm{CN^-}]}{[\mathrm{HCN}]} \] b. \(\mathrm{HOC}_{6} \mathrm{H}_{5}\): Reaction: \[ \mathrm{HOC}_{6} \mathrm{H}_{5} + \mathrm{H}_2 \mathrm{O} \rightleftharpoons \mathrm{H_3 O^+} + \mathrm{OC}_{6} \mathrm{H}_{5}^- \] Ka Expression: \[ K_{\mathrm{a}} = \frac{[\mathrm{H_3 O^+}][\mathrm{OC}_{6} \mathrm{H}_{5}^-]}{[\mathrm{HOC}_{6} \mathrm{H}_{5}]} \] c. \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3}^{+}\): Reaction: \[ \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3}^{+} + \mathrm{H}_2 \mathrm{O} \rightleftharpoons \mathrm{H_3 O^+} + \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_2 \] Ka Expression: \[ K_{\mathrm{a}} = \frac{[\mathrm{H_3 O^+}][\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_2]}{[\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3}^{+}]} \]