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COMEDK · Chemistry · 18. Electrochemistry

What is the quantity of charge, in Faraday units, required for the reduction of 3.5 moles of \(\mathrm{Cr}_2 \mathrm{O} 7^{2-}\) in acid medium?

  1. A 10.5
  2. B 6
  3. C 21
  4. D 3
Verified Solution

Answer & Solution

Correct Answer

(C) 21

Step-by-step Solution

Detailed explanation

The reduction half-reaction for the dichromate ion in an acidic medium is given by: \(\mathrm{Cr}_{2}\mathrm{O}_{7}^{2-} + 14\mathrm{H}^{+} + 6\mathrm{e}^{-} \rightarrow 2\mathrm{Cr}^{3+} + 7\mathrm{H}_{2}\mathrm{O}\) From the balanced equation, it is observed that 1 mole of…