Question

2.5 faradays of electricity is passed through a solution of ${\text{CuS}}{{\text{O}}_{\text{4}}}$. the number of gram equivalent of copper deposited on cathode would be
A) ${\text{1}}$
B) ${\text{2}}$
C) ${\text{2}}{\text{.5}}$
D) ${\text{1}}{\text{.25}}$

Answer 1

Michael Faraday conducted experiments on electrolysis of solutions and melts of electrolytes. He was the first scientist who described the quantitative aspects of the Law of Electrolysis and he gave two laws to explain the same which are known as Faraday’s laws of electrolysis which are first law of electrolysis and second law of electrolysis.

Complete step by step answer:
The process of carrying out non-spontaneous reactions under the influence of electric energy is termed as electrolysis.
Michael Faraday’s ${{\text{1}}^{{\text{st}}}}$ law of electrolysis: The mass of a substance deposited or the mass of gas liberated at a particular electrode is directly proportional to the total amount of charge passing through the electrolyte or solution i.e., ${{m\propto Q}}$ where ‘${\text{m}}$’ is the mass of the substance deposited or liberated on an electrode and ‘${\text{Q}}$’ is the total quantity of electric charge passing through the electrode.
${\text{C}}{{\text{u}}^{{\text{2 + }}}}{\text{ + 2}}{{\text{e}}^{\text{ - }}} \to {\text{Cu}}$(metal)
From Faraday’s ${{\text{1}}^{{\text{st}}}}$ law of electrolysis, the weight of substance deposited by one Faraday of charge is called equivalent weight. One Faraday of electricity will deposit one equivalent amount of copper.
So, ${\text{2}}{\text{.5}}$ Faraday’s of electricity will deposit ${\text{2}}{\text{.5}}$ gram equivalent of copper on the cathode.

So, the correct answer is Option C.

Additional information:
The quantity of electricity is defined as one Faraday and is denoted as F. So, one Faraday is defined as the charge carried per unit mole of electrons. The product or result of an electrolytic reaction depends on the nature of the material being electrolysed and the type of electrodes used.

Note: In case of an inert electrode such as platinum or gold, the electrode doesn’t participate in the chemical reaction and acts only as a source or sink of electrons. In case of reactive electrodes, the electrode participates in the reaction.