Question

The geometry and magnetic behaviour of the complex \([Ni(CO)_4]\) are:

• A. Square planar geometry and diamagnetic
• B. Tetrahedral geometry and diamagnetic
• C. Tetrahedral geometry and paramagnetic
• D. Square planar geometry and paramagnetic

Hint:

The presence of strong field ligands like \( CO \) leads to low spin configurations, affecting geometry and magnetic properties.

Answer 1

The Correct Option is B

Step 1: Finding the oxidation state of Ni.
- Carbonyl (\( CO \)) is a neutral ligand.
- The oxidation state of Ni in \([Ni(CO)_4]\) is \( 0 \).
Step 2: Determining the hybridization.
- The electronic configuration of Ni (Z = 28) is: \[ [Ar] 3d^8 4s^2 \] - In the presence of a strong field ligand like \( CO \), pairing occurs, leading to \( sp^3 \) hybridization.
Step 3: Geometry and magnetism.
- \( sp^3 \) hybridization results in tetrahedral geometry.
- All electrons are paired, making the complex diamagnetic.