The oxidation number of Ba in barium peroxide is

Options

A. `+6`
B. `+2`
C. `1`
D. `+4`

Explanation

To determine the oxidation number of barium (Ba) in barium peroxide (BaO2), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Compound**: The compound in question is barium peroxide, which has the chemical formula BaO2.

2. **Understand the Peroxide Group**: In barium peroxide, the peroxide group (O2) has a specific oxidation state. In peroxides, the oxidation state of each oxygen atom is -1. Therefore, for the two oxygen atoms in BaO2, the total contribution to the oxidation state is:
\[ 2 \times (-1) = -2 \]

3. **Determine the Charge of Barium**: The compound is neutral overall, meaning the total oxidation states must sum to zero. Let the oxidation number of barium be \( x \). The equation can be set up as follows:
\[ x + (-2) = 0 \]

4. **Solve for the Oxidation Number of Barium**: Rearranging the equation gives:
\[ x = +2 \]
Thus, the oxidation number of barium in barium peroxide is +2.

5. **Conclusion**: Therefore, the oxidation number of Ba in barium peroxide (BaO2) is +2.

### Final Answer:
The oxidation number of Ba in barium peroxide is +2.

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