In `AX_3` type of molecule if 'A' undergoes `sp^3 d` hybridisation, then the shape of the molecule is

Options

A. T-shape
B. Octahedral
C. Square pyramidal
D. Tetrahedal

Answer

To determine the shape of an `AX3` type molecule where 'A' undergoes `sp^3d` hybridization, we can follow these steps:

### Step 1: Identify the Hybridization
The hybridization of 'A' is given as `sp^3d`. This indicates that one s orbital, three p orbitals, and one d orbital are involved in the hybridization process.

**Hint:** Remember that `sp^3d` hybridization typically occurs in molecules with five regions of electron density around the central atom.

### Step 2: Determine the Number of Bond Pairs and Lone Pairs
In an `AX3` molecule:
- 'A' is the central atom.
- 'X' represents the surrounding atoms.
- Since there are 3 surrounding atoms (X), we have 3 bond pairs.
- The total number of regions of electron density from `sp^3d` hybridization is 5. Therefore, the remaining 2 regions must be lone pairs.

**Hint:** The total number of electron pairs (bonding + lone pairs) should equal the number of hybrid orbitals formed.

### Step 3: Analyze the Electron Geometry
With 5 regions of electron density (3 bond pairs and 2 lone pairs), we can determine the electron geometry. The arrangement of 5 electron pairs around a central atom corresponds to a trigonal bipyramidal geometry.

**Hint:** Visualize the arrangement of the electron pairs in a trigonal bipyramidal shape, where the bond pairs will occupy the equatorial and axial positions.

### Step 4: Determine the Molecular Shape
Since there are 2 lone pairs, they will occupy the equatorial positions to minimize repulsion (as per VSEPR theory). The remaining 3 bond pairs will occupy the axial positions. This results in a T-shaped molecular geometry.

**Hint:** Remember that lone pairs take up more space than bond pairs, influencing the overall shape of the molecule.

### Conclusion
Therefore, the shape of the `AX3` type molecule where 'A' undergoes `sp^3d` hybridization is **T-shaped**.

**Final Answer:** T-shaped

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