Question

: In the electrolysis of aqueous $NaCl$ , $Na$ is preferentially discharged at mercury cathode forming sodium amalgam. : It is due to the fact that hydrogen has a high over voltage at mercury cathode.

• A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• C. If Assertion is true but Reason is false.
• D. If both Assertion and Reason are false.

Answer 1

Answer: (A)

If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Answer 2

In the electrolysis of a $NaCl$, sodium is preferentially discharged at the mercury cathode forming sodium amalgam ( $Na - Hg$ ) due to the fact that hydrogen has a high over voltage at mercury cathode.