Geometrical shapes of the complexes formed by the reaction of `Ni^(2+)` with ` H2O , Cl^-`, and `CN^- `, respectively are

Options

A. Octahedral, tetrahegral and square planar
B. Tetrahegral, Octahedral and square planar
C. Square planar, tetrahegral and octahedral
D. Octahedral, square planar and tetrahegral

Answer

To determine the geometrical shapes of the complexes formed by the reaction of `Ni^(2+)` with `H2O`, `Cl^-`, and `CN^-`, we will analyze each case step by step.

### Step 1: Reaction of Ni²⁺ with H₂O
1. **Identify the complex formation**: Nickel(II) ion reacts with six water molecules to form a complex.
\[ \text{Ni}^{2+} + 6 \text{H}_2\text{O} \rightarrow \text{[Ni(H}_2\text{O)}_6]^{2+} \]

2. **Determine the electronic configuration**: Nickel has an atomic number of 28, and in the +2 oxidation state, its electronic configuration is:
\[ \text{Ni}^{2+}: [\text{Ar}] 3d^8 4s^0 \]

3. **Hybridization**: The six water molecules act as weak field ligands, which means there will be no pairing of electrons. The hybridization is:
\[ \text{sp}^3\text{d}^2 \]

4. **Geometrical shape**: The geometry corresponding to sp³d² hybridization is octahedral.

### Step 2: Reaction of Ni²⁺ with Cl⁻
1. **Identify the complex formation**: Nickel(II) ion reacts with four chloride ions to form a complex.
\[ \text{Ni}^{2+} + 4 \text{Cl}^- \rightarrow \text{[NiCl}_4]^{2-} \]

2. **Determine the electronic configuration**: The electronic configuration remains the same as before:
\[ \text{Ni}^{2+}: [\text{Ar}] 3d^8 4s^0 \]

3. **Hybridization**: Chloride ions are also weak field ligands, so there will be no pairing of electrons. The hybridization is:
\[ \text{sp}^3 \]

4. **Geometrical shape**: The geometry corresponding to sp³ hybridization is tetrahedral.

### Step 3: Reaction of Ni²⁺ with CN⁻
1. **Identify the complex formation**: Nickel(II) ion reacts with four cyanide ions to form a complex.
\[ \text{Ni}^{2+} + 4 \text{CN}^- \rightarrow \text{[Ni(CN)}_4]^{2-} \]

2. **Determine the electronic configuration**: The electronic configuration remains the same:
\[ \text{Ni}^{2+}: [\text{Ar}] 3d^8 4s^0 \]

3. **Hybridization**: Cyanide ions are strong field ligands, which means they will cause pairing of electrons. The hybridization is:
\[ \text{dsp}^2 \]

4. **Geometrical shape**: The geometry corresponding to dsp² hybridization is square planar.

### Final Summary
- **Ni²⁺ with H₂O**: Octahedral complex
- **Ni²⁺ with Cl⁻**: Tetrahedral complex
- **Ni²⁺ with CN⁻**: Square planar complex

### Conclusion
The geometrical shapes of the complexes formed by the reaction of `Ni^(2+)` with `H2O`, `Cl^-`, and `CN^-` are:
1. Octahedral (with H₂O)
2. Tetrahedral (with Cl⁻)
3. Square planar (with CN⁻)