Limestone on heating gives

Options

A. washing soda
B. plaster of Paris
C. quicklime
D. slaked lime

Explanation

**Step-by-Step Solution:**

1. **Identify the substance:** Limestone is chemically known as calcium carbonate, which has the chemical formula CaCO₃.

2. **Understand the process:** When limestone (CaCO₃) is heated, it undergoes a decomposition reaction. This means that it breaks down into simpler substances.

3. **Write the decomposition reaction:** The heating of calcium carbonate can be represented by the following chemical equation:
\[ \text{CaCO}_3 (s) \xrightarrow{\text{heat}} \text{CaO} (s) + \text{CO}_2 (g) \]
Here, CaO is calcium oxide (also known as quicklime), and CO₂ is carbon dioxide gas.

4. **Identify the products:** From the reaction, we see that the products of heating limestone are:
- Calcium oxide (CaO)
- Carbon dioxide (CO₂)

5. **Conclusion:** Therefore, when limestone is heated, it produces calcium oxide and carbon dioxide.

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