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What actually happens during the process of Electroplating of Copper...??

Observation:

 The copper sulphate solution has copper metal in the dissolved form.

 The copper sulphate solution consists of free positively charged copper ions (Cu ) and
2+
2-
negatively charged sulphate ions (SO4 ).
 When electric current is passed through copper sulphate solution (CuSO4), then the following

changes takes place:
i. The dissolved copper metal present in the copper sulphate solution as positively

2+
charged copper ions (Cu ) gets attracted to the negatively charged electrode iron key.
2+
ii. The positively charged copper ions (Cu ) lose their positive charge on coming in
contact with the negatively charged iron key and form copper atoms (Cu).
iii. These copper atoms deposit on the iron key to form a thin layer of copper metal all

over the surface of iron key.

iv. In this way, copper metal in the electrolyte comes out of the solution and forms a thin
layer on the iron key.

 The copper metal of positively charged copper plate electrode dissolves by forming positively
2+
charged copper ions (Cu ).
 The copper ions thus formed go into the copper sulphate solution.

 In this way, the loss of copper ions from copper sulphate solution (CuSO4) is made up and
the process continues.

 Since the copper ions (Cu ) are taken out from the solution at the negative electrode but put
2+
into solution at the positive electrode, therefore, the concentration of copper sulphate solution

(CuSO4) remains constant.

Inference:

 During copper plating of an iron key, copper metal (Cu) is transferred from the copper plate
to the iron key through the copper sulphate solution (CuSO4).

 In other words, during electroplating with copper, copper metal gets transferred from positive
electrode to the negative electrode.

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