Write the chemical equation and the \(K_{a}\) expression for the dissociation of each of the following acids in aqueous solution. First show the reaction with \(\mathrm{H}^{+}(a q)\) as a product and then with the hydronium ion: \((\mathbf{a}) \mathrm{HNO}_{2},\) (b) \(\mathrm{ClH}_{2} \mathrm{CCOOH}\).

(a) For HNO₂ dissociation with H⁺ as a product: \[\mathrm{HNO}_{2}(aq) \rightleftharpoons \mathrm{H}^{+}(aq) + \mathrm{NO}_{2}^{-}(aq)\] \(K_{a} = \frac{[\mathrm{H}^{+}][\mathrm{NO}_{2}^{-}]}{[\mathrm{HNO}_{2}]}\) With hydronium ion as a product: \[\mathrm{HNO}_{2}(aq) + \mathrm{H}_{2}\mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3}\mathrm{O}^{+}(aq) + \mathrm{NO}_{2}^{-}(aq)\] \(K_{a} = \frac{[\mathrm{H}_{3}\mathrm{O}^{+}][\mathrm{NO}_{2}^{-}]}{[\mathrm{HNO}_{2}]}\) (b) For ClH₂CCOOH dissociation with H⁺ as a product: \[\mathrm{ClH}_{2}\mathrm{CCOOH}(aq) \rightleftharpoons \mathrm{H}^{+}(aq) + \mathrm{ClH}_{2}\mathrm{CCOO}^{-}(aq)\] \(K_{a} = \frac{[\mathrm{H}^{+}][\mathrm{ClH}_{2}\mathrm{CCOO}^{-}]}{[\mathrm{ClH}_{2}\mathrm{CCOOH}]}\) With hydronium ion as a product: \[\mathrm{ClH}_{2}\mathrm{CCOOH}(aq) + \mathrm{H}_{2}\mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3}\mathrm{O}^{+}(aq) + \mathrm{ClH}_{2}\mathrm{CCOO}^{-}(aq)\] \(K_{a} = \frac{[\mathrm{H}_{3}\mathrm{O}^{+}][\mathrm{ClH}_{2}\mathrm{CCOO}^{-}]}{[\mathrm{ClH}_{2}\mathrm{CCOOH}]}\)