Which of the following compounds decomposes on heating?

Options

A. `NaHCO_(3)`
B. `Na_(2)CO_(3)`
C. `CaCO_(3)`
D. `K_(2)SO_(4)`

Answer

To determine which of the given compounds decomposes on heating, we will analyze each compound one by one.

### Step-by-Step Solution:

1. **Understanding Decomposition Reactions**:
- A decomposition reaction occurs when a compound breaks down into simpler products upon heating. We need to identify which of the given compounds undergoes this process.

2. **Analyzing Sodium Bicarbonate (NaHCO3)**:
- When sodium bicarbonate is heated, it decomposes into sodium carbonate (Na2CO3), carbon dioxide (CO2), and water (H2O).
- The reaction can be represented as:
\[ 2 \, \text{NaHCO}_3 \, (s) \rightarrow \text{Na}_2\text{CO}_3 \, (s) + \text{CO}_2 \, (g) + \text{H}_2\text{O} \, (g) \]
- Therefore, sodium bicarbonate decomposes on heating.

3. **Analyzing Sodium Carbonate (Na2CO3)**:
- Sodium carbonate is stable and does not decompose upon heating. It remains as sodium carbonate when heated.

4. **Analyzing Calcium Carbonate (CaCO3)**:
- Calcium carbonate decomposes upon heating to form calcium oxide (CaO) and carbon dioxide (CO2).
- The reaction can be represented as:
\[ \text{CaCO}_3 \, (s) \rightarrow \text{CaO} \, (s) + \text{CO}_2 \, (g) \]
- Thus, calcium carbonate also decomposes on heating.

5. **Analyzing Potassium Sulfate (K2SO4)**:
- Potassium sulfate is stable and does not decompose upon heating. It remains as potassium sulfate when heated.

### Conclusion:
From the analysis, the compounds that decompose on heating are:
- Sodium Bicarbonate (NaHCO3)
- Calcium Carbonate (CaCO3)

### Final Answer:
The compounds that decompose on heating are Sodium Bicarbonate (NaHCO3) and Calcium Carbonate (CaCO3).

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