Chlorine is in `+3` oxidation state in

Options

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

Answer

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

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are HCl, HClO4, ICl, and ClF3.

2. **Analyze HCl**:
- In HCl, hydrogen (H) has an oxidation state of +1.
- Chlorine (Cl) is more electronegative than hydrogen, so it takes a -1 oxidation state.
- Therefore, the oxidation state of chlorine in HCl is **-1**.

3. **Analyze HClO4**:
- In HClO4, hydrogen (H) has an oxidation state of +1.
- Let the oxidation state of chlorine be \( x \).
- Each oxygen (O) has an oxidation state of -2. Since there are 4 oxygen atoms, their total contribution is \( 4 \times (-2) = -8 \).
- The overall charge of the molecule is 0.
- Setting up the equation:
\[ +1 + x + (-8) = 0 \]
\[ x - 7 = 0 \implies x = +7 \]
- Therefore, the oxidation state of chlorine in HClO4 is **+7**.

4. **Analyze ICl**:
- In ICl, chlorine (Cl) is more electronegative than iodine (I).
- Thus, chlorine takes a -1 oxidation state, and iodine takes a +1 oxidation state.
- Therefore, the oxidation state of chlorine in ICl is **-1**.

5. **Analyze ClF3**:
- In ClF3, fluorine (F) has an oxidation state of -1. Since there are 3 fluorine atoms, their total contribution is \( 3 \times (-1) = -3 \).
- Let the oxidation state of chlorine be \( x \).
- The overall charge of the molecule is 0.
- Setting up the equation:
\[ x + (-3) = 0 \]
\[ x = +3 \]
- Therefore, the oxidation state of chlorine in ClF3 is **+3**.

6. **Conclusion**:
- From the analysis, we find that chlorine is in the +3 oxidation state only in **ClF3**.

### Final Answer:
The compound in which chlorine is in the +3 oxidation state is **ClF3**.