Shape of molecule having 4- bond pair and one lone pair is :-

Options

A. Trigonal bipyramidal
B. T-shape
C. See-saw
D. Square planar

Answer

To determine the shape of a molecule with 4 bond pairs and 1 lone pair, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Electron Geometry**:
- For a molecule with 4 bond pairs and 1 lone pair, we first need to identify the total number of electron pairs around the central atom. Here, we have 4 bond pairs and 1 lone pair, which gives us a total of 5 electron pairs.

2. **Determine the Basic Shape**:
- The basic electron geometry for 5 electron pairs is trigonal bipyramidal. In this geometry, there are three equatorial positions and two axial positions.

3. **Account for the Lone Pair**:
- When we have a lone pair, it will occupy one of the equatorial positions to minimize repulsion. This is because lone pairs take up more space than bond pairs, and placing them in the equatorial position helps to reduce the steric hindrance.

4. **Determine the Molecular Shape**:
- With 4 bond pairs and 1 lone pair, the arrangement of the remaining bond pairs will lead to a T-shaped molecular geometry. The three bond pairs will occupy the two equatorial positions and one axial position, while the lone pair occupies one of the equatorial positions.

5. **Conclusion**:
- Therefore, the shape of the molecule with 4 bond pairs and 1 lone pair is T-shaped.

### Final Answer:
The shape of the molecule having 4 bond pairs and 1 lone pair is T-shaped.

---