Oxidation number of Cl in `CaOCl_(2)` ( bleaching powder ) is -

Options

A. Zero, since it contains `Cl_(2)`
B. `-1` , since it contains `Cl^(-)`
C. `+1`, since it contains `ClO^(-)`
D. `+1` and -1 since it contains `ClO^(-)` and `Cl^(-)`

Answer

To determine the oxidation number of chlorine (Cl) in calcium oxychloride (CaOCl₂), also known as bleaching powder, we can follow these steps:

### Step 1: Identify the oxidation states of known elements
In the compound CaOCl₂:
- Calcium (Ca) typically has an oxidation state of +2.
- Oxygen (O) typically has an oxidation state of -2.

### Step 2: Set up the equation for the oxidation states
The overall charge of the compound must be neutral (0). We can express this as:
\[ \text{Oxidation state of Ca} + \text{Oxidation state of O} + 2 \times \text{Oxidation state of Cl} = 0 \]

Substituting the known oxidation states:
\[ +2 + (-2) + 2 \times \text{Oxidation state of Cl} = 0 \]

### Step 3: Solve for the oxidation state of Cl
Now, we simplify the equation:
\[ +2 - 2 + 2 \times \text{Oxidation state of Cl} = 0 \]
This simplifies to:
\[ 2 \times \text{Oxidation state of Cl} = 0 \]
Thus:
\[ \text{Oxidation state of Cl} = 0 \]

### Step 4: Analyze the structure of Cl in CaOCl₂
However, we need to consider that there are two different chlorine atoms in the compound:
- One chlorine is bonded to oxygen (in the form of ClO), and the other is a separate Cl atom.

### Step 5: Assign oxidation states to each Cl
1. For the Cl that is part of ClO:
- The oxidation state of Cl in ClO can be calculated as follows:
\[ \text{Oxidation state of Cl} + (-2) = -1 \]
Thus:
\[ \text{Oxidation state of Cl} = +1 \]

2. For the separate Cl atom:
- The oxidation state of the other Cl (as Cl⁻) is:
\[ \text{Oxidation state of Cl} = -1 \]

### Conclusion
In CaOCl₂, the oxidation states of chlorine are:
- One Cl has an oxidation state of +1 (in ClO).
- The other Cl has an oxidation state of -1.

### Final Answer
The oxidation number of Cl in CaOCl₂ is +1 and -1.

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