Upon heating with $\mathrm{Cu}_{2} \mathrm{~S}$, the reagent(s) that give copper metal is/are

(B) CuO; (C) $\mathrm{Cu}_{2} \mathrm{O}$; (D) $\mathrm{CuSO}_{4}$

JEE Advanced · 2014 · 25 May 2014 · Paper 1 · General Principles and Processes of Isolation of Metals

Upon heating with

Cu_{2} S

, the reagent(s) that give copper metal is/are

Answer: (B), (C), (D)

When

Cu_{2} S

is heated with various copper compounds, reduction to metallic copper occurs:

(B)

Cu_{2} S + 2 CuO \to 6 Cu + SO_{2}

— the sulfide reduces the oxide. Correct.

(C)

Cu_{2} S + 2 Cu_{2} O \to 6 Cu + SO_{2}

— this is the classic self-reduction reaction in copper extraction. Correct.

(D)

Cu_{2} S + 2 CuSO_{4} \to 4 Cu + 3 SO_{2}

— the sulfide reduces the sulfate. Correct.

(A)

CuFeS_{2}

(chalcopyrite) is a copper ore; heating it with

Cu_{2} S

does not directly produce copper metal by a simple reaction. Incorrect.

Official answer: (B), (C), and (D).

JEE Advanced · 2014 · 25 May 2014 · Paper 1 · One or more correct options