Question

What will be the correct order for the wavelengths of absorption in the visible region for the following: [Ni(NO2)6]4−, [Ni(NH3)6]2+, [Ni(H2O)6]2+

Answer 1

Answer:

(Ni(H2O)6)2+,(Ni(NO2)6)4-,(Ni(NO2)6)2+

Answer 2

Answer:

[Ni(H2O)6]2+ > [Ni(NH3)6]2+ > [Ni(NO2)6]4-

Explanation:

In all the three complexes, the central metal ion is the same. Therefore, absorption relies on the ligands in the visible region. Since the the metal ion is corrected, the ligands of the spectro chemical series are in the order of growing field strengths or the CFSE values as : H2O < NH3 < NO2.

Therefore, in the visible region the wavelengths of absorption will be in the order:

[Ni(H2O)6]2+ > [Ni(NH3)6]2+ > [Ni(NO2)6]4-