Question

The mass of the substance deposited when one Faraday of charge is passed through its solution is equal to:
A. Relative equivalent weight
B. Gram equivalent weight
C. Specific equivalent weight
D. None of the above

Answer 1

Hint: This question is asked from the topic of electrolysis. Think about Faraday's law of electrolysis and the formula corresponding to this law. Faraday is the first scientist who gave an idea about the quantitative aspects of electrolysis.

Complete answer:
First, let us look at what electrolysis means. If we cleave the word, we can see that it comprises two parts, ‘electro-‘ and ‘-lysis’. It literally means the cleavage of something using electricity. In electrolysis, the breaking of chemical bonds and the decomposition of chemicals is carried out using electricity. Faraday gives us a relation between the amount of electricity required to produce or liberate a certain amount of substance.
To solve this, we can go through Faraday's second law of electrolysis. It states that during an electrolysis, when an equal amount of electricity passes through the electrolytic solution, a number of different substances liberated are proportional to their chemical equivalent weights.
According to this Faraday’s law of electrolysis, the mass of the substance deposited when one Faraday of charge is passed through its solution is equal to the gram equivalent weight. Let us look at one example to substantiate this answer, when one Faraday of charge is passed through a silver nitrate solution, 108 g of silver is deposited at the cathode which is one gram equivalent of silver nitrate.

Since gram equivalent weight is the answer for this question, the correct option is ‘B. Gram equivalent weight’

Note: One faraday is defined as the amount of charge present on 1 mole of electrons. The value is taken as 96500 Coulomb/mole