Geometrical shapes of the complexes formed by the reaction of Ni ²⁺ with Cl ⁻ , CN ⁻ and H ₂ O , respectively, are

Step-by-step solution

Ni ²⁺+4 CN ⁻ [ Ni ( CN )₄ ]²⁻ . Here Ni ²⁺ has d^8 configuration with CN ⁻ as strong ligand. d^8 -configuration in strong ligand field gives d s p^2 -hybridisation, hence square planar geometry. Ni ²⁺+4 Cl ⁻ [ NiCl ₄ ]²⁻ Here Ni ²⁺ had d^8 -configuration with Cl ⁻ as weak ligand. d^8 -configuration in weak ligand field gives s p^3 hydridisation, hence tetrahedral geometry. Ni ²⁺ with H ₂ O forms [ Ni ( H ₂ O )₆ ]²⁺ complex and H ₂ O is a weak ligand. Therefore, Ni ( H ₂ O )²⁺ has octahedral geometry.