Answer:
Base
Explanations:
Given the reaction expressed as:
[tex]SO_3(g)+O^{2-}(aq)\rightarrow SO_4^{2-}(aq)[/tex]
According to the lewis theory, lewis acid is an ion which accepts a pair of nonbonding electrons. According to the equation above we can see that the oxygen ion donate an electron pair to the central atom SO3 to produce SO4^2-, this makes the oxygen ion the lewis base.
