Maximum bond angle is present in case of

Options

A. `BBr_(3)`
B. `BCl_(3)`
C. `BF_(3)`
D. none of these

Answer

To determine which molecule has the maximum bond angle among BBr3, BCl3, and BF3, we can analyze the bond angles based on the hybridization and the electronegativity of the surrounding atoms.

### Step-by-Step Solution:

1. **Identify the Hybridization**:
- All three molecules (BBr3, BCl3, and BF3) involve boron (B) bonded to three halogen atoms.
- Boron has three valence electrons and forms three bonds, leading to an **sp² hybridization** for all these compounds.

2. **Determine the Steric Number**:
- The steric number is the number of bond pairs plus the number of lone pairs around the central atom.
- For boron in these compounds, there are three bond pairs and no lone pairs, giving a steric number of 3.

3. **Understand the Bond Angles**:
- In an sp² hybridized molecule, the ideal bond angle is 120 degrees. However, the actual bond angle can be influenced by the electronegativity of the surrounding atoms.
- The bond angle is inversely proportional to the electronegativity of the surrounding atoms. This means that as the electronegativity of the halogen increases, the bond angle decreases.

4. **Compare the Electronegativity of Halogens**:
- The electronegativity order of the halogens is: F > Cl > Br.
- Since fluorine (F) is the most electronegative, it will pull the bonding electrons closer, resulting in a smaller bond angle. Chlorine (Cl) is less electronegative than fluorine, and bromine (Br) is the least electronegative among these three.

5. **Conclude the Bond Angles**:
- Given the trend in electronegativity, we can conclude:
- BF3 will have the smallest bond angle.
- BCl3 will have a larger bond angle than BF3 but smaller than BBr3.
- BBr3 will have the largest bond angle due to bromine's lower electronegativity.

6. **Final Answer**:
- Therefore, **BBr3 has the maximum bond angle** among BBr3, BCl3, and BF3.