Chlorine is in `+3` oxidation state in

Options

A. HCl
B. `HClO_(4)`
C. ICl
D. `ClF_(3)`

Explanation

To determine the oxidation state of chlorine in the given compounds, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Compounds**: We have four compounds to analyze:
- Option 1: HCl
- Option 2: HClO4
- Option 3: ICl
- Option 4: ClF3

2. **Calculate Oxidation State in HCl**:
- Let the oxidation state of Cl be \( X \).
- The oxidation state of H is \( +1 \).
- The equation is:
\[ X + 1 = 0 \implies X = -1 \]
- **Conclusion**: In HCl, chlorine is in the \(-1\) oxidation state.

3. **Calculate Oxidation State in HClO4**:
- Let the oxidation state of Cl be \( X \).
- The oxidation state of H is \( +1 \) and O is \( -2 \).
- The equation is:
\[ 1 + X + 4(-2) = 0 \implies 1 + X - 8 = 0 \implies X - 7 = 0 \implies X = +7 \]
- **Conclusion**: In HClO4, chlorine is in the \( +7 \) oxidation state.

4. **Calculate Oxidation State in ICl**:
- Let the oxidation state of Cl be \( X \).
- The oxidation state of I is \( +1 \).
- The equation is:
\[ 1 + X = 0 \implies X = -1 \]
- **Conclusion**: In ICl, chlorine is in the \(-1\) oxidation state.

5. **Calculate Oxidation State in ClF3**:
- Let the oxidation state of Cl be \( X \).
- The oxidation state of F is \( -1 \).
- The equation is:
\[ X + 3(-1) = 0 \implies X - 3 = 0 \implies X = +3 \]
- **Conclusion**: In ClF3, chlorine is in the \( +3 \) oxidation state.

6. **Final Answer**: The compound in which chlorine is in the \( +3 \) oxidation state is **ClF3** (Option 4).