Match the List-I with List-II.
| List-I Compound/substance/catalyst | List-II Metal ion present |
| (A) Chlorophyll | (I) Rh |
| (B) Wilkinson catalyst | (II) Fe |
| (C) Haemoglobin | (III) Mg |
| (D) Vitamin B12 | (IV) Co |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A) - (III), (B) - (I), (C) - (II), (D) - (IV)
Many biological molecules and industrial catalysts are coordination compounds built round a central metal ion.
(A) Chlorophyll — This matches (III) Mg. The green pigment of photosynthesis holds a magnesium ion at its centre.
(B) Wilkinson catalyst — This matches (I) Rh. \( \ce{[(Ph3P)3RhCl]} \) is a rhodium complex used for the hydrogenation of alkenes.
(C) Haemoglobin — This matches (II) Fe. The oxygen carrier of blood is a coordination compound of iron (the haem group).
(D) Vitamin B12 — This matches (IV) Co. Cyanocobalamin, the anti-pernicious anaemia factor, is a coordination compound of cobalt.
Shortcut: The pair (B)–(I) appears only in Option (2).
NCERT (2026-27 edition):
Importance and Applications of Coordination Compounds – …
