when potassium burns in excess supply of air ( oxygen),it forms :-

Options

A. oxide
B. Superoxide
C. Peroxide
D. none

Answer

To solve the question of what potassium forms when it burns in excess oxygen, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: When potassium (K) burns in excess oxygen (O₂), it undergoes a combustion reaction. Potassium is an alkali metal and reacts vigorously with oxygen.

2. **Determine the Product**: The primary products formed when potassium reacts with oxygen are potassium oxide (K₂O), potassium peroxide (K₂O₂), and potassium superoxide (KO₂). The specific product formed depends on the amount of oxygen available.

3. **Excess Oxygen Condition**: Since the question specifies that potassium is burning in excess oxygen, we need to consider the product that forms under these conditions. In excess oxygen, potassium tends to form potassium superoxide (KO₂).

4. **Chemical Composition**:
- Potassium superoxide (KO₂) contains potassium with an oxidation state of +1 and oxygen with an oxidation state of -1/2.
- The formation of superoxide occurs because the excess oxygen allows for the formation of the superoxide ion (O₂²⁻).

5. **Conclusion**: Therefore, when potassium burns in excess supply of air (oxygen), it predominantly forms potassium superoxide (KO₂).

### Final Answer:
The correct answer is **B - Superoxide**.

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