The wavelengths of light absorbed by the complexes ( [ Ni ( H ₂ O )₆ ]²⁺, [ Ni ( en )₃ ]²⁺, [ Ni ( H ₂ O )₄ en ]²⁺ ) are ( ₁, ₂, ₃ ) respectively. The correct order of wavelengths is

Step-by-step solution

The wavelength of the light absorbed by the complexes ( 1 strength of ligands ). Strength of ligand is en ( > H ₂ O ). Hence, energy absorbed would be in order of ( [ Ni ( en )₃ ]²⁺ > [ Ni ( H ₂ O )₄ en ]²⁺ > [ Ni ( H ₂ O )₆ ]²⁺ ) Hence, wavelength order would be ( ( ₁ ) [ Ni ( H ₂ O )₆ ]²⁺ > ( ₃ ) [ ( Ni ( H ₂ O )₄ en ) ] ²⁺ > ( ₂ ) [ Ni ( en )₃ ] ²⁺ ) Hence, ( ( ₁ > ₃ > ₂ ) ).