Write the chemical equation and the \(K_{b}\) expression for the reaction of each of the following bases with water: (a) propylamine,\(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{NH}_{2} ;\) (b) monohydrogen phosphate ion, \(\mathrm{HPO}_{4}^{2-}\); (c) benzoate ion, \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CO}_{2}^{-}\).

(a) The chemical equation for the reaction of propylamine with water is: \( \mathrm{C}_{3} \mathrm{H}_{7} \mathrm{NH}_{2} (\mathrm{aq}) + \mathrm{H}_{2}\mathrm{O} (\mathrm{l}) \rightleftharpoons \mathrm{C}_{3}\mathrm{H}_{7}\mathrm{NH}_{3}^{+}(\mathrm{aq}) + \mathrm{OH}^{-} (\mathrm{aq}) \) The \(K_{b}\) expression is: \( K_{b} = \frac{[\mathrm{C}_{3}\mathrm{H}_{7}\mathrm{NH}_{3}^{+}][\mathrm{OH}^{-}]}{[\mathrm{C}_{3}\mathrm{H}_{7}\mathrm{NH}_{2}]} \) (b) The chemical equation for the reaction of monohydrogen phosphate ion with water is: \( \mathrm{HPO}_{4}^{2-} (\mathrm{aq}) + \mathrm{H}_{2}\mathrm{O} (\mathrm{l}) \rightleftharpoons \mathrm{H}_{2}\mathrm{PO}_{4}^{-} (\mathrm{aq}) + \mathrm{OH}^{-} (\mathrm{aq}) \) The \(K_{b}\) expression is: \( K_{b} = \frac{[\mathrm{H}_{2}\mathrm{PO}_{4}^{-}][\mathrm{OH}^{-}]}{[\mathrm{HPO}_{4}^{2-}]} \) (c) The chemical equation for the reaction of benzoate ion with water is: \( \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CO}_{2}^{-} (\mathrm{aq}) + \mathrm{H}_{2}\mathrm{O} (\mathrm{l}) \rightleftharpoons\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{COOH} (\mathrm{aq}) + \mathrm{OH}^{-} (\mathrm{aq}) \) The \(K_{b}\) expression is: \( K_{b} = \frac{[\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{COOH}][\mathrm{OH}^{-}]}{[\mathrm{C}_{6}\mathrm{H}_{5}\mathrm{CO}_{2}^{-}]} \)