Match List I with List II
| LIST I | LIST II |
| A. \([Co(H_2NCH_2CH_2NH_2)_3]_2(SO_4)_3\) | I. Tetracarbonylnickel(0) |
| B. \([Ni(CO)_4]\) | II. Mercury tetrathiocyanatocobaltate (III) |
| C. \([CoCl_2(en)_2]^+\) | III. tris(ethane-1,2-diamine)cobalt (III) sulphate |
| D. \(Hg[Co(SCN)_4]\) | IV. Dichloridobis(ethane-1,2-diamine)cobalt (III) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A-III, B-I, C-IV, D-II
In IUPAC names of coordination compounds the cation is named first, ligands are named in alphabetical order before the metal, the oxidation state of the metal is given in Roman numerals, and a complex anion takes the ending -ate.
(A) [Co(H2NCH2CH2NH2)3]2(SO4)3 — This matches (III) tris(ethane-1,2-diamine)cobalt (III) sulphate. Three en ligands take the prefix tris; two \( \ce{Co^{3+}} \) balance three \( \ce{SO4^{2-}} \).
(B) [Ni(CO)4] — This matches (I) Tetracarbonylnickel(0). CO is a neutral ligand, so x + 4(0) = 0 and x = 0: nickel is in the zero oxidation state.
(C) [CoCl2(en)2]+ — This matches (IV) Dichloridobis(ethane-1,2-diamine)cobalt (III). Two \( \ce{Cl^{-}} \) and two neutral en give Co: x − 2 = +1, so x = +3.
(D) Hg[Co(SCN)4] — This matches (II) Mercury tetrathiocyanatocobaltate (III). The cobalt is in the complex anion, so its name ends in -ate. With mercury as mercury(I), the anion is \( \ce{[Co(SCN)4]^-} \): x + 4(−1) = −1, so x = +3.