Write an equation for the reaction of each of the following with water:
a. \mathrm{HNO}_{2}
b. \mathrm{HCN}
a. \mathrm{HNO}_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftarrows \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{NO}_{2}^{-}(a q)
b. \mathrm{HCN}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftarrows \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{CN}^{-}(a q)