An aqueous solution of NiCl₂ was heated with excess sodium cyanide in presence of strong oxidizing agent to form [Ni(CN)₆]^2$$-$$. The total change in number of unpaired electrons on metal centre is _______________.

The spin-only magnetic moment value for the complex [Co(CN)₆]^4$$-$$ is __________ BM.

[At. no. of Co = 27]

The total number of unpaired electrons present in the complex K₃[Cr(oxalate)₃] is _____________.

[Ti(H₂O)₆]³⁺ absorbs light of wavelength 498 nm during a d $$-$$ d transition. The octahedral splitting energy for the above complex is ____________ $$\times$$ 10^$$-$$19 J. (Round off to the Nearest Integer). h = 6.626 $$\times$$ 10^$$-$$34 Js; c = 3 $$\times$$ 10⁸ ms^$$-$$1