Question #2799
How can I make the copper get white by salt or acit?
Expert's answer
the metal copper is first converted to blue coloured copper sulphate by the
reaction with concentrated sulphuric acid.
Cu + H2SO4 --> CuSO4 (aq) (Blue)
the solution on evapourasion gives the Blue crystals of CuSO4*5H2O which on
further heating gives anhydrous CuSO4 which is colourless.
CuSO4*5H2O Blue --Heating --> CuSO4 white + 5H2O
Other method is the blue coppersulphate solution will react with ammonium
thiocyanate (NH4NCS) salt solution to give the white (colourless)
precipitate of copper thiocyanate Cu(NCS)2.
reaction with concentrated sulphuric acid.
Cu + H2SO4 --> CuSO4 (aq) (Blue)
the solution on evapourasion gives the Blue crystals of CuSO4*5H2O which on
further heating gives anhydrous CuSO4 which is colourless.
CuSO4*5H2O Blue --Heating --> CuSO4 white + 5H2O
Other method is the blue coppersulphate solution will react with ammonium
thiocyanate (NH4NCS) salt solution to give the white (colourless)
precipitate of copper thiocyanate Cu(NCS)2.
