JEE Main · 2019 · 10 Jan 2019 · Shift 1 · General Principles and Processes of Isolation of Metals

Hall-Herolut's process is given by

(A) $Cu^{2 +} (aq) + H_{2} (g) ⟶ Cu (s) + 2 H^{+} (aq)$
(B) $Cr_{2} O_{3} + 2 Al ⟶ Al_{2} O_{3} + 2 Cr$
(C) $2 Al_{2} O_{3} + 3 C ⟶ 4 Al + 3 CO_{2}$ ✓ Correct
(D) $ZnO + C Coke, 1673 K Zn + CO$

Answer: (C)

Solution

The Hall-Heroult process is the electrolysis of alumina dissolved in molten cryolite, where aluminium is deposited at the cathode and oxide ions are discharged at carbon anodes that burn away as carbon dioxide. Summed up, the overall change is

2 Al X_{2} O X_{3} + 3 C 4 Al + 3 CO X_{2}

. That is the equation representing the process, while the others describe displacement, a thermite reaction and zinc smelting instead.

JEE Main · 2019 · 10 Jan 2019 · Shift 1 · Single correct option

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JEE Main · 2019 · 10 Jan 2019 · Shift 1 · General Principles and Processes of Isolation of Metals

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