Question

According to Faraday’s first law of electrolysis, the amount of any substance deposited at the electrode is directly proportional to the quantity of _______________

(a) Voltage drop

(b) Resistance

(c) Electricity passed

(d) Tolerance

This question was addressed to me during an interview for a job.

I want to ask this question from Faraday’s Laws of Electrolysis topic in chapter Corrosion, Electrolysis, Fuel Cells and Batteries of Engineering Chemistry II

Answer 1

Correct choice is (c) Electricity passed

Explanation: According to Faraday’s law of electrolysis, the amount of any substance deposited at the electrode is directly proportional to the quantity of electricity passed. It is given by:

m = (Q / F) * (M / Z)

where, m = Mass of the substance liberated at an electrode in grams

       Q = Total electric charge passed through the substance in Coulombs

       F = Faraday constant

       M = Molar mass of the substance in grams per mol

       Z = Valency number of ions of the substance

For Faraday’s first law, M, F, and z are constants, so that the larger the value of Q the larger m will be.