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 ammonia (\(\mathrm{NH}_{3}\)) with water as a base is: \(\mathrm{NH}_{3} + \mathrm{H}_{2} \mathrm{O} \rightleftharpoons \mathrm{NH}_{4}^{+} + \mathrm{OH}^{-}\). The corresponding \(K_{\mathrm{b}}\) expression is: \(K_{\mathrm{b}} = \frac{[\mathrm{NH}_{4}^{+}][\mathrm{OH}^{-}]}{[\mathrm{NH}_{3}]}\). b. The reaction of pyridine (\(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{N}\)) with water as a base is: \(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{N} + \mathrm{H}_{2} \mathrm{O} \rightleftharpoons \mathrm{C}_{5} \mathrm{H}_{5} \mathrm{NH}^{+} + \mathrm{OH}^{-}\). The corresponding \(K_{\mathrm{b}}\) expression is: \(K_{\mathrm{b}} = \frac{[\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{NH}^{+}][\mathrm{OH}^{-}]}{[\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{N}]}\).