Question

Consider the following metallurgical processes:(A) Heating impure metal with CO and distilling the resulting volatile carbonyl compound, which is finally decomposed at 150oC - 200oC to get pure metal.(B) Heating the sulphide ore in air until a fraction of it is converted to its oxide and then further heating in the absence of air to allow the oxide to react with unchanged metal sulphide and reduce it to the metallic state.(C) Electrolysis of the molten electrolyte containing approximately equal amounts of the metal chloride and NaCl to obtain the metal.The processes used for obtaining Mg, Ni and Cu, respectively, are

• A. (A) (A), (B) and (C)
• B. (B) (B), (C) and (A)
• C. (C) (C), (A) and (B)
• D. (D) (B), (A) and (C)

Answer 1

Answer: (C)

(C) (C), (A) and (B)

Answer 2

Explanation:
(A)(impure)Ni+4CO−50∘C(NiCO4)]−230∘C( volatie )Ni⏟(pure) +4CO↑This is Mond's process for purification of the metal.(B) Copper is extracted by auto reduction during roasting.Cu2S+32O2⟶ΔCu2O+SO2Cu2S+2Cu2Ohigh temp. 6Cu+SO2(C) Magnesium is extracted by the electrolysis of its halides.MgCl2(s)⟶ eledrolysis Mg2+(l)+2Cl−(1)At cathode: Mg2++2e−⟶Mg(s)At anode: 2Cl−1(1)⟶Cl2(g)+2e−