JEE Main 2023 · 13 April · morning · Single correct · +4 / −1
The mismatched combinations are
A. Chlorophyll - Co
B. Water hardness - EDTA
C. Photography -[Ag(CN)₂]⁻
D. Wilkinson catalyst -[(Ph₃ P)₃ RhCl]
E. Chelating ligand - D-Penicillamine
Choose the correct answer from the options given below :
- (a) A and E Only
- (b) D and E Only
- (c) A and C Only
- (d) A, C, and E Only
Answer and solution
Answer (c) A and C Only
Solution
Chemistry ma’am · 2 steps
Check each pair against the one fact your textbook ties to it. Two of them carry the wrong partner.
- Test each pair. For each item, recall the metal or complex that is actually used, then compare it with the one given.
Pair What is actually true Matched? A. Chlorophyll, Co Chlorophyll has Mg at its centre. Cobalt is found in vitamin B₁₂. Mismatched B. Water hardness, EDTA Titration with EDTA estimates Ca²⁺ and Mg²⁺, which is how hardness is measured. Correct C. Photography, [Ag(CN)₂]⁻ Hypo dissolves unexposed AgBr as [Ag(S₂O₃)₂]³⁻. [Ag(CN)₂]⁻ is used in silver electroplating. Mismatched D. Wilkinson catalyst [(Ph₃P)₃RhCl] is Wilkinson's catalyst, used to hydrogenate alkenes. Correct E. Chelating ligand, D-penicillamine D-penicillamine chelates excess Cu and removes it from the body. Correct - So. Only A and C are mismatched, which is option (c).
The idea to keep. Learn the applications of complexes as fixed pairs: Mg in chlorophyll, Co in vitamin B12, thiosulphate complex in photography, cyanide complex in electroplating, EDTA for hardness.
Answer from the NTA final answer key. Solution by PrepWiser.