JEE Chemistry 2026 Question with Solution

Given: The complex is [Ni(PPh$_3$)$_2$Cl$_2$] and it is stated to be paramagnetic.

Find: Which statements are incorrect.

From the solution, the key idea used is that Ni(II) tetrahedral complexes are paramagnetic, coloured, and do not show geometrical isomerism.

Now evaluate the statements as presented in the solution:

1. Statement A: the solution says the complex exhibits geometrical isomerism and marks A as correct.
2. Statement B: Since paramagnetic nickel complexes are generally coloured, the statement that the complex is white is marked incorrect.
3. Statement C: For $n=2$ unpaired electrons, the spin-only magnetic moment is

So $2.84 \, \text{BM}$ is taken as correct. 4. Statement D: the solution treats this statement as correct. 5. Statement E: Although the explanation discusses a different geometry for Ni(CO)$_4$, the final conclusion of the provided solution includes only A and B as incorrect.

Therefore, following the final conclusion given in the solution, the incorrect statements are A and B only.

The correct option is B.

Note: The detailed reasoning inside the solution contains internal inconsistencies, but the page explicitly concludes that the correct option is B, and that conclusion has been used as the final answer.

Given: The hint says Ni(II) tetrahedral complexes are paramagnetic, coloured, and do not show geometrical isomerism.

Find: Which listed statements are incorrect.

Using that hint directly:

• If the complex is paramagnetic, a spin-only moment near $2.84 \, \text{BM}$ for two unpaired electrons is reasonable, so C is consistent.
• If tetrahedral Ni(II) complexes are coloured, then statement B is incorrect.
• If such complexes do not show geometrical isomerism, then statement A is incorrect.

Hence the incorrect statements are A and B only, which matches option B.