Give any two uses of calcium carbonate.

Explanation

**Step-by-Step Solution:**

1. **Identify Calcium Carbonate**: Calcium carbonate is a chemical compound with the formula CaCO₃. It is a widely used substance in various applications.

2. **First Use - Antacid**: One of the primary uses of calcium carbonate is as an antacid. Antacids are substances that help neutralize stomach acidity. Calcium carbonate is basic in nature, which allows it to effectively counteract excess stomach acid, providing relief from heartburn and indigestion.

3. **Second Use - Laboratory Reagent**: Another significant use of calcium carbonate is as a reagent in the laboratory preparation of carbon dioxide (CO₂). When calcium carbonate is heated, it decomposes to form calcium oxide (CaO) and carbon dioxide gas. This reaction is often used in experiments to generate CO₂.

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