Match the extraction processes listed in Column I with metals listed in Column II:
Column I
(A) Self reduction
(B) Carbon reduction
(C) Complex formation and displacement by metal
(D) Decomposition of iodide
Column II
(P) Lead
(Q) Silver
(R) Copper
(S) Boron
Column I
(A) Self reduction
(B) Carbon reduction
(C) Complex formation and displacement by metal
(D) Decomposition of iodide
Column II
(P) Lead
(Q) Silver
(R) Copper
(S) Boron
Answer: A → I, A → III, B → I, B → III, C → II, D → IV
Solution
Self reduction (A): Copper and lead sulfides undergo self-reduction where part of the sulfide is oxidized to oxide, which then reacts with remaining sulfide to produce the metal. Matches P (Lead) and R (Copper).
Carbon reduction (B): Lead and copper oxides can be reduced by carbon at high temperatures. Matches P (Lead) and R (Copper).
Complex formation and displacement (C): Silver is extracted via cyanide complex formation followed by displacement with zinc (Mac Arthur-Forrest process). Matches Q (Silver).
Decomposition of iodide (D): Boron is purified by van Arkel method involving thermal decomposition of volatile iodide. Matches S (Boron).
Answer: A→P,R; B→P,R; C→Q; D→S
Carbon reduction (B): Lead and copper oxides can be reduced by carbon at high temperatures. Matches P (Lead) and R (Copper).
Complex formation and displacement (C): Silver is extracted via cyanide complex formation followed by displacement with zinc (Mac Arthur-Forrest process). Matches Q (Silver).
Decomposition of iodide (D): Boron is purified by van Arkel method involving thermal decomposition of volatile iodide. Matches S (Boron).
Answer: A→P,R; B→P,R; C→Q; D→S
JEE Advanced · 2006 · 09 Apr 2006 · Match the columns