Write the reaction and the corresponding \(K_{\mathrm{b}}\) equilibrium expression for each of the following substances acting as bases in water. a. \(\mathrm{NH}_{3}\) b. \(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{~N}\)

a. The reaction of \(\mathrm{NH}_3\) as a base in water and its corresponding \(K_\mathrm{b}\) expression are: \[ \mathrm{NH}_{3\,(aq)} + \mathrm{H}_{2 \mathrm{O}_{(l)}} \rightleftharpoons \mathrm{NH}_{4}^{+}_{(aq)} + \mathrm{OH}^{-}_{(aq)} \] \[K_b = \frac{[\mathrm{NH}_{4}^{+}][\mathrm{OH}^{-}]}{[\mathrm{NH}_3]}\] b. The reaction of \(\mathrm{C}_{5}\mathrm{H}_{5}\mathrm{N}\) as a base in water and its corresponding \(K_\mathrm{b}\) expression are: \[ \mathrm{C}_{5}\mathrm{H}_{5}\mathrm{N}_{(aq)} + \mathrm{H}_{2}\mathrm{O}_{(l)} \rightleftharpoons \mathrm{C}_{5}\mathrm{H}_{5}\mathrm{NH}^{+}_{(aq)} + \mathrm{OH}^{-}_{(aq)} \] \[K_b = \frac{[\mathrm{C}_{5}\mathrm{H}_{5}\mathrm{NH}^{+}][\mathrm{OH}^{-}]}{[\mathrm{C}_{5}\mathrm{H}_{5}\mathrm{N}]}\]