The geometry of `[PtCI_(4)]^(2-)`is

Options

A. Tetrahedral
B. Square planar
C. Octahedral
D. Pyramidal

Answer

To determine the geometry of the complex ion \([PtCl_4]^{2-}\), we can follow these steps:

### Step 1: Determine the oxidation state of Platinum (Pt)
- The charge of the complex ion is \(-2\).
- Each chloride ion (\(Cl^-\)) has a charge of \(-1\).
- Since there are 4 chloride ions, their total contribution to the charge is \(4 \times (-1) = -4\).
- Let the oxidation state of platinum be \(x\). The equation can be set up as:
\[ x + (-4) = -2 \]
- Solving for \(x\):
\[ x - 4 = -2 \implies x = +2 \]
- Therefore, the oxidation state of platinum in \([PtCl_4]^{2-}\) is \(+2\).

### Step 2: Determine the electron configuration of Platinum
- Platinum (Pt) has an atomic number of 78. The electron configuration is:
\[ [Xe] 4f^{14} 5d^9 6s^2 \]
- In the \(+2\) oxidation state, it loses 2 electrons, typically from the \(6s\) orbital and one from the \(5d\) orbital:
\[ [Xe] 4f^{14} 5d^8 \]

### Step 3: Identify the hybridization
- Platinum in the \(+2\) oxidation state has a \(5d^8\) configuration.
- The ligands (chloride ions) are considered as strong field ligands, which means they can cause pairing of electrons.
- The hybridization can be determined by the number of ligands and the type of orbitals involved. For \([PtCl_4]^{2-}\), we have 4 chloride ligands.
- The hybridization for this complex is \(dsp^2\).

### Step 4: Determine the geometry
- The geometry associated with \(dsp^2\) hybridization is square planar.
- Therefore, the geometry of \([PtCl_4]^{2-}\) is square planar.

### Final Answer:
The geometry of \([PtCl_4]^{2-}\) is square planar.

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