Which of the following is decomposed on heating?

Options

A. `Na_(2)CO_(3)`
B. `MgCO_(3)`
C. `K_(2)CO_(3)`
D. `Pb_(2)CO_(3)`

Explanation

To determine which of the given compounds decomposes upon heating, we will analyze each option based on their thermal stability.

### Step-by-Step Solution:

1. **Identify the Compounds**: The question provides four compounds. Let's denote them as:
- Option A: Na2CO3 (Sodium Carbonate)
- Option B: K2CO3 (Potassium Carbonate)
- Option C: PbCO3 (Lead Carbonate)
- Option D: MgCO3 (Magnesium Carbonate)

2. **Analyze Na2CO3**:
- Sodium carbonate (Na2CO3) is derived from sodium hydroxide (NaOH), which is a strong base.
- Sodium carbonate is thermally stable and does not decompose upon heating.

3. **Analyze K2CO3**:
- Potassium carbonate (K2CO3) is derived from potassium hydroxide (KOH), which is also a strong base.
- Similar to sodium carbonate, potassium carbonate is thermally stable and does not decompose upon heating.

4. **Analyze PbCO3**:
- Lead carbonate (PbCO3) is known to decompose upon heating. It breaks down into lead oxide (PbO) and carbon dioxide (CO2).
- However, we need to check the last option to confirm.

5. **Analyze MgCO3**:
- Magnesium carbonate (MgCO3) is thermally unstable. When heated, it decomposes into magnesium oxide (MgO) and carbon dioxide (CO2).
- Therefore, MgCO3 does decompose upon heating.

6. **Conclusion**:
- Among the options, both PbCO3 and MgCO3 decompose upon heating. However, since the question asks for one compound, MgCO3 is a well-known example of a compound that decomposes upon heating.

### Final Answer:
The compound that decomposes upon heating is **MgCO3 (Magnesium Carbonate)**.

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