The correct order of the wavelength maxima of the absorption band in the ultraviolet-visible region for the given complexes is
- [Co(CN)6]3- < [Co(NH3)6]3+ < [Co(NH3)5(H2O)]3+ < [Co(NH3)5(Cl)]2+
- [Co(NH3)5(Cl)]2+ < [Co(NH3)5(H2O)]3+ < [Co(NH3)6]3+ < [Co(CN)6]3-
- [Co(CN)6]3- < [Co(NH3)5(Cl)]2+ < [Co(NH3)5(H2O)]3+ < [Co(NH3)6]3+
- [Co(NH3)6]3+ < [Co(CN)6]3- < [Co(NH3)5(Cl)]2+ < [Co(NH3)5(H2O)]3+
Answer
(1) [Co(CN)6]3- < [Co(NH3)6]3+ < [Co(NH3)5(H2O)]3+ < [Co(NH3)5(Cl)]2+
Solution
Absorbed energy = o and max 1 o.
Spectrochemical series: CN- > NH3 > H2O > Cl-.
So o: [Co(CN)6]3- > [Co(NH3)6]3+ > [Co(NH3)5(H2O)]3+ > [Co(NH3)5Cl]2+.
max follows the reverse order: [Co(CN)6]3- < [Co(NH3)6]3+ < [Co(NH3)5(H2O)]3+ < [Co(NH3)5Cl]2+.
Answer: (A)