Which of the following has largest bond angle ?

Options

A. `H_(2)O`
B. `F_(2)O`
C. `Cl_(2)O`
D. `H_(2)S`

Answer

To determine which of the given molecules (H2O, F2O, Cl2O, and H2S) has the largest bond angle, we can follow these steps:

### Step 1: Identify the molecular structures and lone pairs
- **H2O (Water)**: The oxygen atom has two lone pairs and forms two O-H bonds.
- **F2O (Difluorooxide)**: The oxygen atom has two lone pairs and forms two O-F bonds.
- **Cl2O (Dichlorine monoxide)**: The oxygen atom has two lone pairs and forms two O-Cl bonds.
- **H2S (Hydrogen sulfide)**: The sulfur atom has two lone pairs and forms two S-H bonds.

### Step 2: Understand the effect of lone pairs on bond angles
According to VSEPR (Valence Shell Electron Pair Repulsion) theory:
- Lone pair-lone pair repulsion > Lone pair-bond pair repulsion > Bond pair-bond pair repulsion.
- The presence of lone pairs tends to compress the bond angles between the bonded atoms.

### Step 3: Compare the sizes of the bonded atoms
- **H2O**: The bond angle is approximately 104.5°.
- **F2O**: Fluorine is larger than hydrogen, which increases the bond angle due to greater repulsion, estimated around 102°.
- **Cl2O**: Chlorine is larger than both hydrogen and fluorine, which increases the bond angle further, estimated around 110°.
- **H2S**: The bond angle is approximately 92.1° due to the larger size of sulfur compared to oxygen.

### Step 4: Analyze the bond angles
Based on the above comparisons:
- H2O has a bond angle of 104.5°.
- F2O has a bond angle of approximately 102°.
- Cl2O has a bond angle of approximately 110°.
- H2S has a bond angle of 92.1°.

### Step 5: Conclusion
The molecule with the largest bond angle is **Cl2O**, with an estimated bond angle of approximately 110°.

### Final Answer:
**Cl2O** has the largest bond angle among the given options.

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