Exams › JEE Advanced › Chemistry
By passing a fixed current through molten salts for two hours, 40 kg of calcium is deposited. Using the identical current for the same two-hour interval, how much aluminium would be liberated? (Atomic masses: Ca = 40, Al = 27)
- 22 kg
- 18 kg
- 9 kg
- 27 kg
Correct answer: 18 kg
Solution
Equal charge deposits equal gram-equivalents. Equivalents of Ca = 40000/(40/2) = 2000. So equivalents of Al = 2000 too. Mass of Al = equivalents * (27/3) = 2000 * 9 = 18000 g = 18 kg.
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