posted by molly .
what is the effects of NH3(aq) and HCl(aq) on the CuSO4 or NiCl2 solution
It isn't clear what solution you are talking about but NH3 complexes both Cu and Ni for form Cu(NH3)4^2+ and Ni(NH3)4^2+. If the HCl is added to these complexes the NH3 is neutralized and the original Cu ions and Ni ions are formed. Concentrated HCl will form CuCl4^2- and NiCl4^2-