Halogens react with oxygen to form many oxoacids , commonly named as hypohalous acid , halous acid , halic acid and perhalic acid . The halogen(s) which form (s) halous acid is/are

Options

A. `F_(2)`
B. `Cl_(2)`
C. `Cl_(2) , Br_(2)` and `I_(2)`
D. `F_(2) , Cl_(2)` and `Br_(2)`

Answer

To determine which halogen(s) can form halous acid, we need to analyze the different types of oxoacids formed by halogens when they react with oxygen.

### Step-by-Step Solution:

1. **Understanding Halous Acid**:
Halous acid has the general formula \( \text{HOXO} \), where \( X \) represents the halogen. The oxidation state of the halogen in halous acid is +3.

2. **Identifying Halogens**:
The halogens are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). We need to check which of these can form halous acid.

3. **Formation of Halous Acid**:
- **Chlorine (Cl)**: Chlorine can form chlorous acid (\( \text{HClO}_2 \)).
- **Bromine (Br)**: Bromine can also form bromous acid (\( \text{HBrO}_2 \)).
- **Iodine (I)**: Iodine can form iodous acid (\( \text{HIO}_2 \)).
- **Fluorine (F)**: Fluorine does not form a stable halous acid.

4. **Conclusion**:
The halogens that can form halous acid are chlorine (Cl), bromine (Br), and iodine (I). However, among these, chlorine is the most commonly recognized halogen that forms a stable halous acid.

5. **Final Answer**:
The halogen(s) which form halous acid is/are chlorine (Cl).