What mass of chromium could be deposited by electrolysis of an aqueous solution of Cr₂(SO₄)₃ for 155 min using a constant current of 10.0 A? (F = 96485 C/mol)

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Quizplus · Accepted Answer

The charge passed is calculated using Q = It = 10 A * 155 * 60 s = 93000 C. The moles of electrons are 93000 C / 96485 C/mol = 0.964 mol. Chromium has a valency of 3, so moles of Cr = 0.964 mol / 3 = 0.321 mol. The mass of Cr is 0.321 mol * 52 g/mol = 16.7 g.

What Mass of Chromium Could Be Deposited by Electrolysis of an Aqueous