The correct order of the wavelength of light absorbed by the given coordination entities is: (A) [Co(H₂O)₆]³⁺ (B) [Co(NH₃)₆]³⁺ (C) [Co(CN)₆]³⁻

Step-by-step solution

The central metal ion in all the given complexes is Co³⁺ . According to the spectrochemical series, the field strength of the ligands follows the order: H₂O The crystal field splitting energy ( _ o ) increases with the strength of the ligand. Thus, the order of _ o for the complexes is: [Co(H₂O)₆]³⁺ The energy of the absorbed light is equal to the crystal field splitting energy, and is inversely proportional to the wavelength ( ), since E = _ o = hc . Therefore, the wavelength of absorbed light follows the reverse