An octahedral metal - cyanide complex with the formula [M(H_2O)_5CN]^+ absorbs v
ID: 1016014 • Letter: A
Question
An octahedral metal - cyanide complex with the formula [M(H_2O)_5CN]^+ absorbs visible light with a wavelength of 450 nm. This complex participates in a ligand substitution reaction to produce the closely related complex [M(H_2O)_5Cl]^+. What would you predict about the wavelength of visible light that the chloride complex absorbs, relative to that absorbed by the cyanide complex? The chloride complex will absorb visible light with a longer wavelength that the cyanide complex. The chloride complex will absorb visible light with a shorter wavelength that the cyanide complex. The chloride complex will absorb visible light with the same wavelength as the cyanide complex. It is impossible to predict the wavelength of visible light absorbed by the chloride complex relative to the cyanide complex.Explanation / Answer
Splitting of orbital through Cl- ligand is smaller than compare to CN- ligand.
Thus the lower the splitting , the less energy is required to promote an electron from the lower group of orbitals to the higher groups of orbitals.
In term of wavelength we can say that longer wavelength (lower energy).
Thus the correct answer is the chloride complex will absorb visible light with a longer wave length that the cyanide complex.
E= hv
E= hv/