Match List-I with List-II
| List-I (Complex/Ion) | List-II (Use/Application) |
| (A) [Ag(S2O3)2]3− | (I) Anti-tumours |
| (B) [(Ph3P)3RhCl] | (II) Estimation of hardness of water |
| (C) Cis-[Pt(NH3)2(Cl)2] | (III) Photography |
| (D) Na2EDTA | (IV) Hydrogenation of alkenes |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
Coordination compounds have important uses in photography, catalysis, medicine and chemical analysis. Each complex in List-I is known for one such use:
(A) \( \ce{[Ag(S2O3)2]^{3-}} \) — This matches (III) Photography. In fixing a photographic film, the unexposed AgBr is dissolved by hypo (sodium thiosulphate) as this soluble complex ion.
\( \displaystyle \ce{AgBr + 2Na2S2O3 -> Na3[Ag(S2O3)2] + NaBr} \)
(B) \( \ce{[(Ph3P)3RhCl]} \) — This matches (IV) Hydrogenation of alkenes. This is Wilkinson’s catalyst, used for the homogeneous hydrogenation of alkenes.
\( \displaystyle \ce{RCH=CH2 + H2} \xrightarrow{[(\mathrm{Ph_3P})_3\mathrm{RhCl}]} \ce{RCH2CH3} \)
(C) Cis-\( \ce{[Pt(NH3)2(Cl)2]} \) — This matches (I) Anti-tumours. Cisplatin binds to the DNA of cancer cells and stops them from dividing; it is used in the treatment of tumours.
(D) Na2EDTA — This matches (II) Estimation of hardness of water. Hardness is due to \( \ce{Ca^{2+}} \) and \( \ce{Mg^{2+}} \) ions, which form very stable complexes with EDTA. Titrating water against Na2EDTA therefore measures its hardness.
\( \displaystyle \ce{Ca^2+ + EDTA^4- -> [Ca(EDTA)]^2-} \)
Shortcut: (D)–(II) appears only in Option (4).
NCERT (2026-27 edition):
Importance and Applications of Coordination Compounds – “… Hardness of water is estimated by simple titration with Na2EDTA. … Coordination compounds are used as catalysts for many industrial processes. Examples include rhodium complex, [(Ph3P)3RhCl], a Wilkinson catalyst, is used for the hydrogenation of alkenes. … In black and white photography, the developed film is fixed by washing with hypo solution which dissolves the undecomposed AgBr to form a complex ion, [Ag(S2O3)2]3–. … Some coordination compounds of platinum effectively inhibit the growth of tumours. Examples are: cis–platin and related compounds.”