Question

A charge of 96500 coulomb liberates ............. from the solution of CuSO₄.

• A. 63.5 gm copper
• B. 31.76 gm copper
• C. 96500 gm copper
• D. 100 gm copper

Hint:

To find the mass of a substance liberated in electrolysis, use Faraday’s laws and remember that 96500 coulombs corresponds to 1 mole of substance for monovalent ions.

Answer 1

The Correct Option is A

Step 1: Faraday's laws of electrolysis.
According to Faraday’s laws of electrolysis, the amount of substance liberated at an electrode is directly proportional to the quantity of charge passed through the electrolyte. The equation is: \[ m = \frac{M \times Q}{F \times n} \] where \( m \) is the mass of the substance, \( M \) is the molar mass, \( Q \) is the charge, \( F \) is the Faraday constant, and \( n \) is the valence of the ion. For CuSO₄, the molar mass of copper is 63.5 g, and 96500 coulombs liberates one mole of copper. Step 2: Analysis of options.
(A) 63.5 gm copper: Correct — 96500 coulombs liberates 63.5 grams of copper, which is the equivalent of one mole of copper.
(B) 31.76 gm copper: This is incorrect; 31.76 grams would correspond to half a mole of copper.
(C) 96500 gm copper: This is incorrect, as it is too large a quantity.
(D) 100 gm copper: This is incorrect, as it does not match the molar equivalent of copper.
Step 3: Conclusion.
The correct answer is (A) because 96500 coulombs liberates 63.5 grams of copper.