Chapter 18, Problem 42A

Interpretation Introduction

Interpretation: The reason for jewelry to be often manufactured by plating an expensive metal needs to be explained.

Concept Introduction: An electric current is used in electroplating to minimize the dissolved metal cations to build a thin coating on the electrode. In anions electrical oxidation, electroplating is also applied to a solid surface, such as the deposition of AgCl on Ag wire to form silver chloride electrodes.

Answer to Problem 42A

Jewelry is manufactured by plating an expensive metal like gold over a cheaper metal by electroplating to prevent corrosion.

Explanation of Solution

Electroplating is a process through which a metallic layer is coated on another metal by applying electric current. This is helpful to prevent corrosion or to produce an expensive metallic layer on a cheap metal.

The expensive metal act as anode and the metal which is plated acts as a cathode. The solution must contain ions of the desired plating material in the cell. On applying electric current, the reduction of ions takes place and it gets deposited on the metal taken as cathode.

Conclusion

Electroplating is simply the method coating one metal onto the other, primarily to avoid metal corrosion.