On heating `KMnO_(4)`, one among the following is not formed:

Options

A. `K_(2)MnO_(4)`
B. `O_(2)`
C. `MnO_(2)`
D. `MnO`.

Explanation

To solve the question regarding the decomposition of potassium permanganate (KMnO₄) upon heating, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Decomposition Reaction**:
When potassium permanganate (KMnO₄) is heated, it undergoes a decomposition reaction. The general reaction can be represented as:
\[ 2 \text{KMnO}_4 \rightarrow \text{K}_2\text{MnO}_4 + \text{MnO}_2 + \text{O}_2 \]

2. **Identify the Products**:
From the decomposition reaction, we can identify the products formed:
- Potassium manganate (K₂MnO₄)
- Manganese dioxide (MnO₂)
- Oxygen gas (O₂)

3. **Analyze the Options Given**:
The options provided in the question are:
- A) Potassium manganate (K₂MnO₄)
- B) Manganese dioxide (MnO₂)
- C) Oxygen (O₂)
- D) Manganese oxide (MnO)

From our decomposition reaction, we see that K₂MnO₄, MnO₂, and O₂ are indeed produced.

4. **Determine Which is Not Formed**:
The only compound from the options that does not appear as a product in the decomposition of KMnO₄ is manganese oxide (MnO). Therefore, MnO is not formed during this reaction.

5. **Conclusion**:
The correct answer to the question is that manganese oxide (MnO) is not formed when potassium permanganate is heated.

### Final Answer:
Manganese oxide (MnO) is not formed when KMnO₄ is heated.

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