Which gas is produced when coal burns in air?

Options

A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Hydrogen

Explanation

To answer the question "Which gas is produced when coal burns in air?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Coal Composition**:
- Coal is primarily composed of carbon. When we refer to coal, we are essentially talking about a carbon-rich substance.

2. **Combustion Process**:
- Combustion is a chemical reaction that occurs when a substance reacts with oxygen. In this case, coal (carbon) is reacting with oxygen from the air.

3. **Chemical Reaction**:
- The chemical equation for the combustion of carbon can be represented as:
\[ \text{C} + \text{O}_2 \rightarrow \text{CO}_2 \]
- Here, C represents carbon (from coal) and O2 represents oxygen.

4. **Gas Produced**:
- During the combustion of coal, carbon combines with oxygen to produce carbon dioxide (CO2) gas.

5. **Heat Production**:
- It is important to note that combustion reactions also release heat energy. This is a characteristic of combustion.

6. **Final Answer**:
- Therefore, the gas produced when coal burns in air is carbon dioxide (CO2).

### Summary:
The gas produced when coal burns in air is carbon dioxide (CO2).

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