What chemical will form a precipitate w/ aqueous CuCl2, but not aqueous MgCl2?

Question

It's not NH3 from what I've learned so far. CuCl2 will ppt with any soluble salt of a silver group, but will MgCl2 as well?

Question 2: I need a reagent that will form a ppt with soln of Cu(NO3)2, but not with a soln of Sb(NO3)3. All I could find here is that Cu2+ will ppt with neutral and negative ligands.

Answer 1

You need to consult a table of solubilities and a table of activity series of metals. They will answer this problem.