Chapter 16, Problem 74E

Each of the following is a Lewis acid-base reaction. Which reactant is the acid, and which is the base? Explain.
(a) ${\text{SO}}_3+{\text{H}}_{\text{2}}\text{O}\to {\text{H}}_2{\text{SO}}_{\text{4}}$
(b) $\text{Zn}\left(\text{OH}\right)\left(\text{s}\right){\text{+2OH}}^{\text{-}}\left(\text{aq}\right)\to {\left[\text{Zn}{\left(\text{OH}\right)}_{\text{4}}\right]}^{\text{2-}}\left(\text{aq}\right)$