Question:medium

How much charge is required for the 1 mol \( \mathrm{Al^{3+}} \) to Al?

Show Hint

Number of Faradays required = number of electrons involved in the half-reaction.
  • 1F
  • 2F
  • 4F
  • 3F

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The Correct Option is D

Solution and Explanation

To find out how much charge is required to convert 1 mole of \( \mathrm{Al^{3+}} \) ions to Al metal, we need to consider the stoichiometry of the reduction process and Faraday's laws of electrolysis.

The reduction of \( \mathrm{Al^{3+}} \) to Al involves the following half-reaction:

\(\mathrm{Al^{3+} + 3e^- \rightarrow Al}\)

This equation shows that 3 moles of electrons are required to reduce 1 mole of \( \mathrm{Al^{3+}} \) ions to metallic Al.

Faraday's constant (\( F \)) is the charge of one mole of electrons, approximately \( 96500 \) coulombs per mole.

Therefore, the total charge required for this process is:

\(3 \, \text{moles of } e^- \times F = 3F\)

Thus, the required charge to convert 1 mole of \( \mathrm{Al^{3+}} \) to Al is 3F, which is the correct answer.

Conclusion: The correct option is 3F, because it matches the stoichiometry of the electron transfer required in the reduction of \( \mathrm{Al^{3+}} \) to Al.

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