Chemistry (solubility)

Question

Why are most phosphates not soluble while most hydroxides are soluble?

Answer 1

Hmmm.... According to my table of solubility about 14 phosphate salts are insoluble and around 13 hydroxide salts are insoluble. I really don't see the big difference and so it is difficult to answer the question.

Maybe someone else can shed additional light on this issue.