Q.

Match List–I with List–II.                    [2025]

  List-I   List-II
  (Complex)   (Hybridisation of central metal ion)
(A) [CoF6]3- (I) d2sp3
(B) [NiCl4]2- (II) sp3
(C) [Co(NH3)6]3+ (III) sp3d2
(D) [Ni(CN)4]2- (IV) dsp2

 

Choose the correct answer from the options given below:

1 (A)–(III), (B)–(IV), (C)–(I), (D)–(II)  
2 (A)–(III), (B)–(II), (C)–(I), (D)–(IV)  
3 (A)–(I), (B)–(II), (C)–(III), (D)–(IV)  
4 (A)–(I), (B)–(IV), (C)–(III), (D)–(II)  

Ans.

(2)

(A) [CoF6]3-

Oxidation number of Co=+3

Co3+=[Ar]183d6

F- is a weak field ligand. It cannot pair up d electrons. Thus 4d orbitals are used for sp3d2 hybridization. Six e- pairs from six F- are accommodated in these six sp3d2 orbitals.

(B) [NiCl4]2-

Oxidation number of Ni=+2

Ni2+:[Ar]183d8

Cl- is a weak field ligand; hence does not cause pairing of 3d8 electrons. Ni2+ undergoes sp3 hybridization and lone pairs from Cl- are accommodated in sp3 orbitals.

(C) [Co(NH3)6]3+

Oxidation number of Co=+3

Co3+=[Ar]183d6

NH3 is a strong field ligand. It pairs up d electrons. After pairing d electrons, two 3d orbitals are vacant. Co3+ undergoes d2sp3 hybridization by using two 3d orbitals. Six e- pairs from six NH3 are accommodated in these six d2sp3 orbitals.

(D) [Ni(CN)4]2-

Oxidation number of Ni=+2

Ni2+:[Ar]183d8

CN- is a strong field ligand; hence causes pairing of 3d8 electrons, then causes dsp2 hybridization using 3d,4s, and 4p orbitals.