Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II. 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:

Both Statement I and Statement II are incorrect

Statement I is incorrect but Statement II is correct

Statement I is correct but Statement II is incorrect

Chemistry · Coordination Compounds

JEE Main 2024 — 1 February, Shift 1 — Question 63

Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II.

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:

Option A:
Both Statement I and Statement II are incorrect
Option B:
Both Statement I and Statement II are correct
Correct
Option C:
Statement I is incorrect but Statement II is correct
Option D:
Statement I is correct but Statement II is incorrect

Answer: B

Step-by-step solution

Statement I is Correct: The complex $\left[\mathrm{Ni(H_2O)_6}\right]^{2+}$ contains $\mathrm{Ni^{2+}}$ ( $d^8$ configuration) with $\mathrm{H_2O}$ as a weak field ligand. Hence, it has unpaired electrons and shows $d$ - $d$ transitions, giving a green colour.

Statement II is Correct: In $\left[\mathrm{Ni(CN)_4}\right]^{2-}$ , $\mathrm{CN^-}$ is a strong field ligand which causes pairing of electrons, forming a square planar, low-spin complex with no unpaired electrons. Therefore, the complex is colourless.

Thus, both Statement I and Statement II are correct (Option B).

Answer key and solution verified before publishing.

Practise Coordination Compounds

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Solve a similar one free

Exam: JEE Main 2024
Paper: 1 February, Shift 1
Subject: Chemistry
Chapter: Coordination Compounds
Topic: Properties and importance of Coordination Complexes

Which of the following complex is homoleptic?

Answer: B

Step-by-step solution

Practise Coordination Compounds

More Coordination Compounds questions from this paper