Which of the following is an acidic oxide ?

Options

A. `Mn_2O_7`
B. `Mn_3O_4`
C. `MnO`
D. `Mn_2O_3`

Explanation

To determine which of the following is an acidic oxide, we need to analyze the oxidation states of the metals in the given oxides and their corresponding acidic character.

### Step-by-Step Solution:

1. **Understanding Acidic Oxides**:
Acidic oxides are typically formed by non-metals or metals in high oxidation states. The acidic character increases with the increase in oxidation state of the metal.

2. **Identifying the Oxides**:
Let's consider the oxides mentioned in the video transcript:
- **Mn2O7**
- **Mn3O4**
- **MnO**

3. **Calculating Oxidation States**:
- For **Mn2O7**:
- Let the oxidation state of Mn be \( x \).
- The equation becomes: \( 2x + 7(-2) = 0 \)
- Solving for \( x \):
\[ 2x - 14 = 0 \implies 2x = 14 \implies x = +7 \]
- Therefore, the oxidation state of Mn in Mn2O7 is +7.

- For **Mn3O4**:
- The oxide is a mixed oxide of MnO and Mn2O3.
- In MnO, Mn has an oxidation state of +2.
- In Mn2O3, Mn has an oxidation state of +3.
- Thus, in Mn3O4, the average oxidation state can be calculated, but it is lower than +7.

- For **MnO**:
- The oxidation state of Mn is +2.

4. **Comparing Acidic Characters**:
- The acidic character increases with the oxidation state.
- Mn2O7 has the highest oxidation state of +7, which indicates it is the most acidic oxide among the three.

5. **Conclusion**:
- Therefore, the acidic oxide from the options provided is **Mn2O7**.