Copper sulfides qualitative

During the traditional qualitative inorganic analytical procedure, samples containing the lead and salicylate radicals can lead to the formation and possible detonation of lead picrate. This arises dining evaporation of the filtrate with nitric acid, after precipitation of the copper-tin group metals with hydrogen sulfide. Salicylic acid is converted under these conditions to picric acid, which in presence of lead gives explosive lead picrate. An alternative (MAQA) scheme is described which avoids this possibility. 

The most important applications of hydrogen sulfide involve the production of sodium sulfide and other inorganic sulfides. Hydrogen sulfide obtained as a by-product often is converted into sulfuric acid. It also is used in organic synthesis to make thiols or mercaptans. Other applications are in metallurgy for extracting nickel, copper, and cobalt as sulfides from their minerals and in classical qualitative analytical methods for precipitation of many metals (see Reactions). It also is used in producing heavy water for nuclear reactors. 

Many schemes oF qualitative analysis involve separation of the copper-group sulfides (PbS, CuS, CdS) horn the tin-group sulfides (HgS,... 

Describe how you would separate the metal ions in a solution containing silver ion, copper(II) ion, and nickel(II) ion, using the sulfide scheme of qualitative analysis. 

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