AP EAMCET Engineering 17 Sep 2020 Shift 1 Paper

Complexes, (I) [Ni(NH3)6]2+
(II) [Ni(H2O)6]2+ and (III) [Ni(NO2)6]4− are made of Ni2+ and ligands −NH3,−H2O and −NO2− respectively. The field strength order of the ligands is
H2O<NH3<NO2−
So, the order CFSE values: ∆0II<∆0I<∆0III
We know, E=‌

hc

λ

or E∝‌

1

λ

So, the order of wavelength of absorption in visible region will be,
λIII<λI<λII