Which statement is incorrect?

Options

A. `Ni(CO)_(4)` - tetrahedral, paramagnetic
B. `Ni(CN)_(4)^(2-)` square planar, diamagnetic
C. `Ni(CO)_(4)`tetrahedral, diamagnetic
D. `[Ni(CI)_(4)]^(-2)` tetrahedral, paramagnetic

Answer

To determine which statement is incorrect regarding the coordination compounds discussed, we will analyze the properties of each compound mentioned in the video transcript step by step.

### Step 1: Analyze Ni(CO)₄
- **Compound**: Ni(CO)₄
- **Oxidation State of Ni**: 0 (since CO is a neutral ligand)
- **Electron Configuration**: Ni has the electron configuration [Ar] 3d⁸ 4s².
- **Hybridization**: CO is a strong field ligand, which causes pairing of electrons. Thus, the hybridization is sp³.
- **Magnetism**: Since all electrons are paired, Ni(CO)₄ is diamagnetic.
- **Shape**: The geometry of sp³ hybridization is tetrahedral.

### Step 2: Analyze Ni(CN)₄²⁻
- **Compound**: Ni(CN)₄²⁻
- **Oxidation State of Ni**: Let x be the oxidation state. CN is -1, so:
\[ x + 4(-1) = -2 \implies x - 4 = -2 \implies x = +2 \]
- **Electron Configuration**: Ni²⁺ has the configuration [Ar] 3d⁸.
- **Hybridization**: CN is a strong field ligand, which causes pairing of electrons. The hybridization is dsp², leading to a square planar geometry.
- **Magnetism**: Since all electrons are paired, Ni(CN)₄²⁻ is diamagnetic.

### Step 3: Analyze NiCl₄²⁻
- **Compound**: NiCl₄²⁻
- **Oxidation State of Ni**: Let x be the oxidation state. Cl is -1, so:
\[ x + 4(-1) = -2 \implies x - 4 = -2 \implies x = +2 \]
- **Electron Configuration**: Ni²⁺ has the configuration [Ar] 3d⁸.
- **Hybridization**: Cl is a weak field ligand, which does not cause pairing. The hybridization is sp³.
- **Magnetism**: Since there are unpaired electrons, NiCl₄²⁻ is paramagnetic.

### Conclusion
Now, let's summarize the findings:
1. **Ni(CO)₄**: Tetrahedral, diamagnetic (correct).
2. **Ni(CN)₄²⁻**: Square planar, diamagnetic (correct).
3. **NiCl₄²⁻**: Tetrahedral, paramagnetic (correct).

The incorrect statement is regarding the hybridization and magnetic properties of NiCl₄²⁻, which is incorrectly stated as diamagnetic when it is actually paramagnetic.

### Final Answer
The incorrect statement is regarding NiCl₄²⁻ being diamagnetic; it is actually paramagnetic.

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