Given below are two statements: Statement (I): A solution of $\left[\mathrm{Ni}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$ is green in colour. Statement (II): A solution of $\left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}$ is colourless. In the light of the above statements, choose the most appropriate answer from the options given below:

(B) Both Statement I and Statement II are correct

(A) Both Statement I and Statement II are incorrect

(C) Statement I is incorrect but Statement II is correct

(D) Statement I is correct but Statement II is incorrect

JEE Main · 2024 · 01 Feb 2024 · Shift 1 · Coordination Compounds

Given below are two statements:

Statement (I): A solution of

[Ni (H_{2} O)_{6}]^{2 +}

is green in colour.
Statement (II): A solution of

[Ni (CN)_{4}]^{2 -}

is colourless.

In the light of the above statements, choose the most appropriate answer from the options given below:

(A)Both Statement I and Statement II are incorrect
(B)Both Statement I and Statement II are correct✓ Correct
(C)Statement I is incorrect but Statement II is correct
(D)Statement I is correct but Statement II is incorrect

Answer: (B)

Solution

[Ni(H_{2} O)_{6}]^{2 +}

has unpaired d-electrons (weak-field aqua ligand, no pairing), giving a green colour due to d-d transitions — Statement I is correct.

[Ni(CN)_{4}]^{2 -}

has

CN^{-}

, a strong-field ligand that causes pairing of all d-electrons, giving a diamagnetic, colourless (no d-d transition possible) square planar complex — Statement II is also correct. Both statements are correct.

JEE Main · 2024 · 01 Feb 2024 · Shift 1 · Single correct option

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JEE Main · 2024 · 01 Feb 2024 · Shift 1 · Coordination Compounds

Solution

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