Statement (I): Dimethyl glyoxime forms a six-membered covalent chelate when treated with NiCl₂ solution in presence of NH₄OH. Statement (II): Prussian blue precipitate contains iron both in (+2) and (+3) oxidation states.
In the light of the above statements, choose the most appropriate answer from the options given below:
(A)Statement I is false but Statement II is true✓ Correct
(B)Both Statement I and Statement II are true
(C)Both Statement I and Statement II are false
(D)Statement I is true but Statement II is false
Answer: (A)
Solution
Dimethylglyoxime coordinates to Ni2+ through its two oxime nitrogens; each ligand closes a five-membered chelate ring with the metal (Ni–N=C–C=N), not a six-membered one, and the two rings are further linked by intramolecular O–H···O hydrogen bonds to give the characteristic square-planar red precipitate — Statement I, which claims a six-membered ring, is false. Prussian blue, Fe4[Fe(CN)6]3, holds Fe3+ ions outside the complex and Fe2+ ions coordinated inside the hexacyanoferrate(II) unit, so it genuinely contains iron in both the +2 and +3 states — Statement II is true.
JEE Main · 2024 · 01 Feb 2024 · Shift 2 · Single correct option
