什么与氨水反应生成沉淀后再加氨水溶解

硝酸银或含有Cu2+的溶液。离子方程式：Ag+ + NH3。H2O == AgOH↓ + NH4+,AgOH + 2NH3。H2O == [Ag(NH3)2]+ + OH- + 2H2OCu2+ + 2NH3。H2O == Cu(OH)2↓ + 2NH4+,Cu(OH)2 + 4NH3。H2O == [Cu(NH3)4]2+ + 2OH- + 4H2O