Consider the following octahedral complexes of cobalt: I. [Co(H₂O)₆]³⁺ II. [Co(NH₃)₆]³⁺ III. [Co(CN)₆]³⁻ The correct increasing order of the wavelengths of light absorbed by these complexes is:

Step-by-step solution

The energy of the light absorbed by a coordination complex is equal to its crystal field splitting energy ( _o ). According to the spectrochemical series, the strength of the given ligands increases in the order: H₂O A stronger ligand field produces a larger crystal field splitting. Therefore, the order of _o for the given complexes is: [Co(H₂O)₆]³⁺ (I) The wavelength of absorbed light ( ) is inversely proportional to the energy absorbed ( _o = hc ). Thus, the complex with the highest splitting energy will absorb l