Chapter U1.27, Problem 3E

Interpretation Introduction

Interpretation:

Method to remove a coating from an object is to be described.

Concept introduction:

Electroplating is a method used to coat the surface of an object with a pure metal of choice. Less expensive metals can be covered with thin layers of other metals like gold. Today it is used industrially to extract aluminium from its compounds.

Answer to Problem 3E

One can remove the coating from an object by reversing the electroplating process. The object whose coating is to be removed is made the anode (positive terminal) and other electrode is made the cathode (negative terminal).

Explanation of Solution

Reverse electroplating - The setup for this process is same as normal electroplating process except that the electrodes are reversed. For example, if onehas to remove copper coating from a steel object, the positive end of battery is connected to the object whose coating is to be removed. The negative terminal of battery is connected to a nickel strip. The electrolyte used is copper sulfate. When the circuit is complete, the copper coating comes off the object and enters the solution. Copper moves in opposite direction and deposits on nickel strip which is connected to negative terminal.

Conclusion

Electroplating can be used to coat a surface with metal as well as to remove coating from objects.