Question:
The colour of the coordination compounds depends on the crystal field splitting. What will be the correct order of absorption of wavelength of light in the visible region, for the complexes, [Co(NH3)6]3+, [Co(CN)6]3–, [Co(H2O)6]3+
(i) [Co(CN)6]3–> [Co(NH3)6]3+>[Co(H2O)6]3+
(ii) [Co(NH3)6]3+> [Co(H2O)6]3+> [Co(CN)6]3–
(iii) [Co(H2O)6]3+> [Co(NH3)6]3+> [Co(CN)6]3–
(iv) [Co(CN)6]3–> [Co(NH3)6]3+> [Co(H2O)6]3+
Solution:
Option (iii) [Co(H2O)6]3+> [Co(NH3)6]3+> [Co(CN)6]3– is the answer.