Easy MCQ +4 / -1 PYQ · JEE Mains 2024

The reaction at cathode in the cells commonly used in clocks involves.

  1. A oxidation of $\mathrm{Mn}$ from +2 to +7
  2. B reduction of $\mathrm{Mn}$ from +4 to +3 Correct answer
  3. C oxidation of $\mathrm{Mn}$ from +3 to +4
  4. D reduction of $\mathrm{Mn}$ from +7 to +2

Solution

<p>In the cells commonly used in clocks, specifically alkaline batteries, the reaction at the cathode involves the reduction of manganese dioxide (MnO<sub>2</sub>). The manganese in MnO<sub>2</sub> is initially in the +4 oxidation state, and it gets reduced to the +3 oxidation state. Thus, the correct reaction occurring at the cathode can be represented as follows:</p> <p>The correct answer is:</p> <p>Option B<br>reduction of $\mathrm{Mn}$ from +4 to +3</p>

About this question

Subject: Chemistry · Chapter: Electrochemistry · Topic: Electrochemical Cells

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