When potassium is reacted with oxygen, which of the following compound(s) is/are formed?

Options

A. `K_(2)O`
B. `KO_(2)`
C. Both `K_(2)O and KO_(2)`
D. `K_(2)O_(2)`

Answer

To determine the compound(s) formed when potassium reacts with oxygen, we can follow these steps:

### Step 1: Understand the Reaction
When potassium (K) reacts with oxygen (O2), it forms a compound. The nature of the compound depends on the type of oxide that potassium forms with oxygen.

### Step 2: Identify the Type of Oxide
Potassium is an alkali metal, and alkali metals typically form oxides, peroxides, or superoxides when reacting with oxygen.

- **Oxides**: Formed by the reaction of metals with oxygen in a 1:1 ratio (e.g., K2O).
- **Peroxides**: Formed when the metal reacts with oxygen in a 1:2 ratio (e.g., K2O2).
- **Superoxides**: Formed when the metal reacts with oxygen in a 1:1 ratio with an additional oxygen (e.g., KO2).

### Step 3: Determine the Specific Compound for Potassium
For potassium, it is known that it primarily forms superoxide (KO2) when it reacts with oxygen. This is due to the larger size of the potassium ion (K+) compared to the oxide ion (O2-), which stabilizes the superoxide formation.

### Step 4: Write the Reaction
The reaction can be represented as:
\[ 4K + O2 \rightarrow 2K2O2 \] (for peroxide) or
\[ 4K + O2 \rightarrow 2KO2 \] (for superoxide).

However, potassium predominantly forms superoxide in the presence of excess oxygen.

### Conclusion
When potassium reacts with oxygen, the primary compound formed is potassium superoxide (KO2).

### Final Answer
The compound formed when potassium reacts with oxygen is **potassium superoxide (KO2)**.

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