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Electroplating











Electroplating is the process of plating one metal onto another by hydrolysis. Electroplating is mainly done for protection (specially against corrosion) and for decorative purposes. 

 How does electroplating work?












As shown in the diagram the victim electrode or the donor is the anode. So, for the anode we select an element which can donate ions that are necessary for electroplating. 

 As shown above, the battery pulls  regular streams of electrons over from the anode and supplies them to the cathode.

 The cell is filled with a solution of a salt of the metal to be plated and an aqueous solution of salt slightly acidic in nature is used for this purpose.

 In this experiment, NiCl2 ionizes in the water into Ni++ ions and two parts of Cl- ions.

At the cathode - 

 Because the object being plated is negatively charged, it attracts Ni++ ions in the solution. Thus all the Ni++ ions migrate and get attracted to the cathode.

 Due to the electrons that the cathode receives from the anode, electrons convert these Ni++ ions into Ni metal.

 Ni++ + 2e → Ni

 Furthermore we can conclude that the amount of metal that gets accumulated at the cathode (the object being electroplated) is directly proportional to the number of electrons that the battery provides.

 At the anode-

 At the anode, electrons are removed from the metal and oxidized into the Ni++ state.

 Ni → Ni++ + 2e

 Thus, it should be clear that the Ni metal rod dissolves providing Ni++ to the solution.












These Ni++ ions now migrate towards the cathode and the electrons also move towards the cathode  as described earlier.

 Thus, the Ni rod dissolves and the cathode gains mass (Ni). The solution becomes concentrated with Ni++ ions or NiCl2 solution.
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