JEE Main202624 January 2026Evening ShiftChemistryCoordination CompoundsActual
The wavelength of light absorbed for the following complexes are in the order ( (I) [ Co ( NH ₃ )₆ ]³⁺ ; (II) [ Co ( H ₂ O )₆ ]³⁺ ; (III) [ Co ( CN )₆ ]³⁻ ; (IV) [ Co ( NH ₃ )₅ ( H ₂ O ) ]³⁺ ; (V) [ CoF ₆ ]³⁻ )
Options
- AIII < I < IV < V < II
- BIII < I < IV < II < V
- CIII < I < II < IV < V
- DIII < IV < I < II < V
Correct answer
B. III < I < IV < II < V
Step-by-step solution
Wavelength of light absorbed increases as C.F.S.E of complex decreases. [Co(CN)₆]³⁻ has maximum CFSE [CoF₆]³⁻ has least CFSE Ligand field strength ; C.F.S.E Correct wavelength order. V > II > IV > I > III