Question

Assertion :If a certain charge liberate 0.8 g of oxygen, 10.8 g of silver can liberated by the same amount of charge. Reason: From Faraday's first law of electrolysis, the amount of charge liberated is proportional to the mass of the substance taken.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

According to Faraday's first law, the mass of the substance liberated or deposited on an electrode during electrolysis is directly proportional to the quantity of electric charge passed through the electrolyte. Therefore, if m is the mass of a substance liberated or deposited at an electrode due to the passage of charge q, then according to Faraday's law of electrolysis,

$m\propto q$ or $m=zq$

Where z is a constant of proportionality and is called electrochemical equivalent of the substance. So we get,

$\frac{m_1}{m_2}=\frac{z_1}{z_2}$

$\therefore \frac{0.8}{m_2}=\frac{8}{108}$

$m_2=\frac{0.8\times 108}{8}=10.8g$