NEETChemistryCoordination Compounds
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The complex [ PtCl ₄]²⁻ is diamagnetic, while [ NiCl ₄]²⁻ is paramagnetic. Reason (R): Platinum is a 5d transition metal, and for 4d and 5d series metals, the crystal field splitting is very large, causing even weak field ligands like Cl ^- to force electron pairing. In the light of the above state
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
In the complex [ NiCl ₄]²⁻ , the central metal ion is Ni ²⁺ which has a 3d^8 electronic configuration. Since Cl ^- is a weak field ligand, it does not cause pairing of electrons. The complex undergoes sp^3 hybridization, forming a tetrahedral geometry with 2 unpaired electrons, making it paramagnetic. In the complex [ PtCl ₄]²⁻ , the central metal ion is Pt ²⁺ which has a 5d^8 electronic configuration. For metals in the 4d and 5d transition series, the effective nuclear charge is higher and the d-orbitals are more