Question

What would the cation in a salt have to do to make a solution acidic? What would the anion in a salt have to do to make a solution basic?

Answer 1

A cation have to be able to donor a proton H+ to water,
Such as NH4+ cation can do that.

An anion can accept a proton in a water solution.
Basic anions are for example S2-, CH3COO-