Cu2+andNi2+ions give black precipitate withH2Sin presence ofHClsolution
Ferric ion gives blood red colour with potassium thirocyanate
Cu2+salts give red coloured borax bead test in reducing flame.
Cu2+ion gives chocolate coloured precipitate with potassium ferrocyanide solution
Cu2+ ion does not give chocolate coloured precipitate with potassium ferrocyanide solution instead it forms white precipitate. The reaction can be as follow: K4[Fe(CN)6] + 2CuSO4 → Cu2[Fe(CN)6] + 2K2SO4