The geometries of the ammonia complexes of `Ni^(2+),Pt^(2+)` and `Zn^(2+)`, respectively, are

Options

A. octahedral, square planar and tetrahedral
B. square planar, octahedral and tetrahedral
C. tetrahedral, square planar and octahedral
D. octahedral, tetrahedral and square planar

Answer

To determine the geometries of the ammonia complexes of Ni²⁺, Pt²⁺, and Zn²⁺, we will analyze each metal ion's electronic configuration and the nature of ammonia as a ligand.

### Step 1: Analyze the ammonia complex of Ni²⁺

1. **Complex Formation**: The ammonia complex of nickel is represented as Ni(NH₃)₆²⁺.
2. **Electronic Configuration**: The electron configuration of Ni²⁺ is [Ar] 3d⁸.
3. **Nature of Ligand**: Ammonia (NH₃) is a weak field ligand, which means it does not cause significant pairing of electrons in the d-orbitals.
4. **Hybridization**: For Ni²⁺ with a 3d⁸ configuration and NH₃ as a weak field ligand, the hybridization will be sp³d².
5. **Geometry**: The geometry corresponding to sp³d² hybridization is octahedral.

### Step 2: Analyze the ammonia complex of Pt²⁺

1. **Complex Formation**: The ammonia complex of platinum is represented as Pt(NH₃)₄²⁺.
2. **Electronic Configuration**: The electron configuration of Pt²⁺ is [Xe] 4f¹⁴ 5d⁸.
3. **Nature of Ligand**: Ammonia (NH₃) is a strong field ligand, especially for 4d and 5d transition metals.
4. **Hybridization**: For Pt²⁺ with a 5d⁸ configuration and NH₃ as a strong field ligand, the hybridization will be dsp².
5. **Geometry**: The geometry corresponding to dsp² hybridization is square planar.

### Step 3: Analyze the ammonia complex of Zn²⁺

1. **Complex Formation**: The ammonia complex of zinc is represented as Zn(NH₃)₄²⁺.
2. **Electronic Configuration**: The electron configuration of Zn²⁺ is [Ar] 3d¹⁰.
3. **Nature of Ligand**: Ammonia (NH₃) is a weak field ligand.
4. **Hybridization**: For Zn²⁺ with a 3d¹⁰ configuration, the d-orbitals are fully filled, and the hybridization will be sp³.
5. **Geometry**: The geometry corresponding to sp³ hybridization is tetrahedral.

### Summary of Geometries

- **Ni(NH₃)₆²⁺**: Octahedral
- **Pt(NH₃)₄²⁺**: Square planar
- **Zn(NH₃)₄²⁺**: Tetrahedral

### Final Answer

The geometries of the ammonia complexes of Ni²⁺, Pt²⁺, and Zn²⁺ are octahedral, square planar, and tetrahedral, respectively.