Discussion Forum



1)

Geometrical shapes of the complexes formed by the reaction of $Ni^{2+}$ with $Cl^{-}$,  $CN^{-}$ and $H_{2}O$ , respectively, are 


A) octahedral, tetrahedral and square planar

B) tetrahedral, square planar and octahedral

C) square planar, tetrahedral and octahedral

D) octahedral, square planar and octahedral

Answer:

Option B

Explanation:

 $Ni^{2+}+4CN^{-} \rightarrow  [Ni(CN)_{4}]^{2-}$ . Here $Ni^{2+}$  has d8 configuration with CN- as strong ligand.

9122021676_g3.PNG

$d^{8}$  configuration in strong ligand field  gives dsp2-hybridisation  , hence  square planar geometry 

$Ni^{2+} +4Cl^{-} \rightarrow  [NiCl_{4}]^{2-}$

 Here  $Ni^{2+}$ has $d^{8}$ -configuration with $Cl^{-}$ as weak  ligand 

 912202116_g4.PNG

 d8-configuration in weak ligand field gives sp3 hybridisation, hence  tetrahedral geometry  Ni2+ with H2O forms 

  $[Ni(H_{2}O)_{6}]^{2+}$ complex  and H2O is a weak  ligand 

 9122021457_g5.PNG

 

 Therefore , $Ni(H_{2}O)^{2+}$  has octahedral  geometry