Combustion of coal and petroleum products releases :

Options

A. NaO
B. `CO_2`
C. `MgO`
D. `P_2O_5`

Answer

**Step-by-Step Solution:**

1. **Understanding Combustion**: The question refers to the combustion of coal and petroleum products. Combustion is a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light.

2. **Identifying Main Constituents**: Coal and petroleum are primarily composed of carbon (C). When these substances are burned, the carbon reacts with oxygen (O2) from the air.

3. **Chemical Reaction**: The primary reaction during the combustion of carbon can be represented as:
\[ C + O_2 \rightarrow CO_2 \]
This equation shows that carbon (C) combines with oxygen (O2) to form carbon dioxide (CO2).

4. **Main Product of Combustion**: The main product released from the combustion of coal and petroleum is carbon dioxide (CO2). This gas is a significant contributor to air pollution and is a greenhouse gas.

5. **Conclusion**: Therefore, the correct answer to the question is that the combustion of coal and petroleum products releases carbon dioxide (CO2).

**Final Answer**: CO2

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