Chapter 4, Problem 4.39CP

Assume that an aqueous solution Of a cation, represented as a blue sphere, is allowed to mix with a solution Of an anions represented as a red sphere, and that the following result is obtained:

Which combinations of cation and anion, chosen from the following lists, are compatible with the observed results? Explain.

Cations: $N{a}^{+},C{a}^{2+},A{g}^{+},N{i}^{2+}$

Anions: $C{l}^{-},C{O}_3^{2+},Cr{O}_4^{2-},N{O}_3^{-}$