The pair having similar hybrid geometry is :

Options

A. `BF_3,NH_3`
B. `H_2O,C_2H_2`
C. `CO_2,SO_2`
D. `CH_4H_2O`

Answer

To solve the question regarding which pair has similar hybrid geometry, we will analyze the hybridization and geometry of each compound mentioned in the transcript.

### Step-by-Step Solution:

1. **Identify the Compounds:**
- The compounds mentioned are BF3, NH3, H2O, C2H2, CO2, SO2, and CH4.

2. **Determine the Hybridization and Geometry of Each Compound:**
- **BF3 (Boron Trifluoride):**
- Boron has 3 valence electrons and forms 3 sigma bonds with fluorine.
- Steric number = 3 (3 sigma bonds + 0 lone pairs).
- Hybridization = sp².
- Geometry = Trigonal planar.

- **NH3 (Ammonia):**
- Nitrogen has 5 valence electrons and forms 3 sigma bonds with hydrogen.
- Steric number = 4 (3 sigma bonds + 1 lone pair).
- Hybridization = sp³.
- Geometry = Tetrahedral.

- **H2O (Water):**
- Oxygen has 6 valence electrons and forms 2 sigma bonds with hydrogen.
- Steric number = 4 (2 sigma bonds + 2 lone pairs).
- Hybridization = sp³.
- Geometry = Bent (but still classified as tetrahedral due to the arrangement of electron pairs).

- **C2H2 (Acetylene):**
- Each carbon has 4 valence electrons and forms 1 sigma bond with hydrogen and a triple bond with another carbon.
- Steric number = 2 (2 sigma bonds + 0 lone pairs).
- Hybridization = sp.
- Geometry = Linear.

- **CO2 (Carbon Dioxide):**
- Carbon has 4 valence electrons and forms 2 sigma bonds with oxygen.
- Steric number = 2 (2 sigma bonds + 0 lone pairs).
- Hybridization = sp.
- Geometry = Linear.

- **SO2 (Sulfur Dioxide):**
- Sulfur has 6 valence electrons and forms 2 sigma bonds with oxygen.
- Steric number = 3 (2 sigma bonds + 1 lone pair).
- Hybridization = sp².
- Geometry = Bent (but also classified as trigonal planar due to the arrangement of electron pairs).

- **CH4 (Methane):**
- Carbon has 4 valence electrons and forms 4 sigma bonds with hydrogen.
- Steric number = 4 (4 sigma bonds + 0 lone pairs).
- Hybridization = sp³.
- Geometry = Tetrahedral.

3. **Identify Pairs with Similar Hybrid Geometry:**
- From the analysis:
- NH3 and H2O both have sp³ hybridization and are tetrahedral in geometry (though H2O is bent).
- CH4 also has sp³ hybridization and is tetrahedral in geometry.
- BF3 and SO2 have sp² hybridization and trigonal planar geometry.
- C2H2 and CO2 have sp hybridization and linear geometry.

4. **Conclusion:**
- The pairs that have similar hybrid geometry are:
- **NH3 and H2O** (both tetrahedral).
- **BF3 and SO2** (both trigonal planar).
- **C2H2 and CO2** (both linear).
- However, the question asks for a specific pair, and the most straightforward answer is **H2O and CH4** as both are tetrahedral.

### Final Answer:
The pair having similar hybrid geometry is **H2O and CH4**.