In an electrochemicalcell, dichromate ions in aqueous acidic medium are reduced to Cr 3+ . The current (in amperes) that flows through the cell for 48.25 minutes to produce 1 mole of Cr 3+ is . Use: 1 Faraday =96500 C mol -1

Chemistry · Electrochemistry

JEE Advanced 2025 — Paper 1 — Question 37

In an electrochemicalcell, dichromate ions in aqueous acidic medium are reduced to $\mathrm{Cr}^{3+}$ . The current (in amperes) that flows through the cell for 48.25 minutes to produce

1 mole of $\mathrm{Cr}^{3+}$ is $\qquad$ . Use: 1 Faraday $=96500 \mathrm{C} \mathrm{mol}^{-1}$

Answer: 100

Numerical answer — enter this value.

Step-by-step solution

For reduction of dichromate, balanced reaction is : $\mathrm{Cr}_{2} \mathrm{O}_{7}{ }^{-2}(\mathrm{aq})+6 \mathrm{e}^{-}+14 \mathrm{H}^{+}(\mathrm{aq}) \rightarrow 2 \mathrm{Cr}^{3+}(\mathrm{aq})+7 \mathrm{H}_{2} \mathrm{O}(l)$

3 mol 1 mol Number of Farads required $=3 \mathrm{~mol}$

Let current $=\mathrm{I}$ amperes $\Rightarrow \frac{\mathrm{I} \times 48.25 \times 60}{96500}=3$

$\mathrm{I}=100 \mathrm{~A}$

Answer key and solution verified before publishing.

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Exam: JEE Advanced 2025
Paper: Paper 1
Subject: Chemistry
Chapter: Electrochemistry
Topic: Faraday's Laws