急救!!!!!!!!

I think you should first find out what is insoluble in water under room condition
1. All bromides, iodides, chlorides of silver and lead are insoluble
2. All metal carbonates and metal hydroxides except that of Potassium, Sodium
3. All sulphates are soluable except that of barium and lead (Calcium sulphate is sparingly soluable)

First get all chloride out
MgCl2 or FeCl3 or BaCl2+ AgNO3 will have precipitation
Than carbonate
(None)
Than sulphate
CuSO4 +BaCl2
Than similar to hydorxides
BesidesMgCl2
Al2(SO)3
FeCl3
CuSO4
AgNO3
BaCl2
These when disolved in water, they form solution, not solvent!

MgCl2+AgNO3
BaCl2+AgNO3
BaCl2+CuSO4
BaCl2+Al2(SO)3 (若不是在酸性環境下)