Which of the following is true about the complex `[PtCl_(2)(H_(2)O)(NH_(3))]`?

Options

A. It exhibits geomettrical isomerism
B. It is paramagnetic complex
C. its geometry is tetrahedron
D. platinum is `sp^(3)` hybridised

Explanation

To determine which statement is true about the complex \([PtCl_2(H_2O)(NH_3)]\), we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Ligands and Their Charges:**
- The complex contains three different ligands:
- Chloride ions \((Cl^-)\) with a charge of \(-1\) (two of them).
- Water \((H_2O)\) which is a neutral ligand (charge \(0\)).
- Ammonia \((NH_3)\) which is also a neutral ligand (charge \(0\)).

2. **Set Up the Equation for Oxidation State:**
- Let the oxidation state of platinum be \(X\).
- The total charge of the complex is \(0\).
- Therefore, we can set up the equation:
\[ X + 2(-1) + 0 + 0 = 0 \]
- Simplifying this gives:
\[ X - 2 = 0 \implies X = +2 \]

3. **Determine the Electron Configuration of Platinum:**
- Platinum (Pt) has an atomic number of \(78\). The electron configuration in the ground state is:
\[ [Xe] 4f^{14} 5d^9 6s^1 \]
- For platinum in the \(+2\) oxidation state, we remove two electrons (usually from the \(6s\) and \(5d\) orbitals):
\[ [Xe] 4f^{14} 5d^8 \]

4. **Determine the Hybridization:**
- The ligands are \(Cl^-\), \(H_2O\), and \(NH_3\). Since there are four ligands, we can expect a square planar geometry.
- The hybridization for a square planar complex is \(dsp^2\).

5. **Check for Magnetic Properties:**
- Since the \(5d\) subshell has \(8\) electrons and all are paired, the complex is **diamagnetic**.

6. **Determine the Geometry:**
- The geometry of the complex is square planar due to the \(dsp^2\) hybridization.

7. **Check for Isomerism:**
- The complex can exhibit geometrical isomerism due to the presence of two identical ligands (chlorides). It can exist in cis and trans forms.

### Conclusion:
The correct statement about the complex \([PtCl_2(H_2O)(NH_3)]\) is that it exhibits geometrical isomerism.