Chapter 22, Problem 16STP

Interpretation Introduction

Interpretation:

The correct statement needs to be chosen to electroplate an iron fork with silver.

Concept introduction:

In electroplating experiment, layer of one metal is formed on another metal to protect it from oxidation and other degradation processes.

Answer to Problem 16STP

Correct Answer: Option (b)

Explanation of Solution

Reason for correct option:

An iron fork can undergo oxidation if exposed to moisture in the air. To prevent it from oxidation, a layer of silver can be formed on it.

This is done such that silver at anode gets oxidized to form silver ion and reaches to the cathode where electrode of iron is present and reduction of silver ion to silver takes place on iron electrode. Therefore, the silver electrode must have more mass than fork so that the desired thick layer of silver can be formed.

Therefore, option (b) is correct.

Conclusion

Reason for incorrect option: Since, reduction takes place at iron electrode, it acts as cathode and silver electrode acts as anode. Thus, statement (b) cannot be correct. Since, oxidation of silver takes place thus; electric current must be applied to silver electrode. Therefore, statement (c) cannot be correct. In cell solution, silver ions are present which reaches the cathode and reduced to silver to form layer on the iron electrode. Thus, statement (d) is incorrect. In the electroplating experiment, power supply supplied direct current which results in the oxidation at anode. Thus, the electric current cannot be pulsed. The statement (e) is incorrect.