Look at the solubility guidelines (Table 4.1). Using your knowledge of periodic trends and the energetics of formation of solutions, explain why cations derived directly from alkali metals are usually soluble, but this is less the case for alkaline earth metals. Also, discuss how these would be affected in the case of solvation with sulfide ions. You should be clear about the identity of the relevant intermolecular forces as well as periodic trends leading to such differences.
No equations, the Solubility guidelines referred to is a fairly standard solubility guide telling what ions in water will typically form precipitates. It looks a lot like this:
The Attempt at a Solution
I was thinking that the solvation energy might be stronger than the lattice energy of the ionic compounds that might form from the +1 charged alkali metals than in the +2 charged alkali metals, since ionic bond strength is proportionate to charge. But many alkali earth metals are soluble in water with the sulfide ion, so my idea doesn't seem to make sense there. Thanks in advance.