2) (5 points) Write the equilibrium constant equations for the following equations: \text { a) } \mathrm{NH}_{4}^{+} \leftrightarrow \mathrm{NH}_{3}+\mathrm{H}^{+} \text { b) } \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \leftrightarrow 2 \mathrm{Al}^{3+}+3 \mathrm{SO}_{4}^{2}