Which of the manganese oxides is the most acidic from the given options ?

Options

A. `Mn_2O_3`
B. `MnO`
C. `MnO_2`
D. `Mn_2O_7`

Answer

To determine which manganese oxide is the most acidic, we need to analyze the oxidation states of manganese in the given oxides. The acidic character of metal oxides generally increases with the oxidation state of the metal. Here’s a step-by-step solution:

### Step 1: Identify the manganese oxides
Let's consider the common manganese oxides:
1. MnO
2. MnO2
3. Mn2O3
4. MnO4 (as in KMnO4)

### Step 2: Determine the oxidation state of manganese in each oxide
- **For MnO**:
- Let the oxidation state of Mn be \( x \).
- The equation is \( x - 2 = 0 \) (since O is -2).
- Therefore, \( x = +2 \).

- **For MnO2**:
- Let the oxidation state of Mn be \( x \).
- The equation is \( x - 4 = 0 \).
- Therefore, \( x = +4 \).

- **For Mn2O3**:
- Let the oxidation state of Mn be \( x \).
- The equation is \( 2x - 6 = 0 \).
- Therefore, \( x = +3 \).

- **For MnO4 (in KMnO4)**:
- Let the oxidation state of Mn be \( x \).
- The equation is \( x - 8 = 0 \).
- Therefore, \( x = +7 \).

### Step 3: Compare the oxidation states
Now we have the oxidation states:
- MnO: +2
- MnO2: +4
- Mn2O3: +3
- MnO4: +7

### Step 4: Determine the most acidic oxide
The acidic character increases with the oxidation state. Therefore, the oxide with the highest oxidation state, which is MnO4 (where Mn is +7), will be the most acidic.

### Conclusion
Thus, the most acidic manganese oxide among the given options is **MnO4**.

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