`NH_(3)` can't be obtained by :

Options

A. heating of `NH_(4)NO_(3) " or " NH_(4)NO_(2)`
B. heating of `NH_(4)Cl " or " (NH_(4))_(2) CO_(3)`
C. heating of `NH_(4)NO_(3) " with " NaOH`
D. reaction of AlN or `Mg_(3)N_(2) " or " CaCN_(2) " with " H_(2)O`

Answer

To solve the question "NH₃ can't be obtained by:", we need to analyze the given processes and determine which one does not produce ammonia (NH₃).

### Step-by-Step Solution:

1. **Identify the Processes**: The question lists several processes involving ammonium compounds. We will evaluate each process to see if it produces ammonia.

2. **Evaluate Heating of NH₄NO₃ (Ammonium Nitrate)**:
- When ammonium nitrate (NH₄NO₃) is heated, it decomposes to produce nitrous oxide (N₂O) and water (H₂O).
- **Conclusion**: Ammonia (NH₃) is **not** produced in this reaction.

3. **Evaluate Heating of NH₄NO₂ (Ammonium Nitrite)**:
- When ammonium nitrite (NH₄NO₂) is heated, it decomposes to produce nitrogen gas (N₂) and water (H₂O).
- **Conclusion**: Ammonia (NH₃) is **not** produced in this reaction.

4. **Evaluate Heating of NH₄Cl (Ammonium Chloride)**:
- When ammonium chloride (NH₄Cl) is heated, it decomposes to produce ammonia (NH₃) and hydrogen chloride (HCl).
- **Conclusion**: Ammonia (NH₃) **is** produced in this reaction.

5. **Evaluate Heating of NH₄O₂CO₃ (Ammonium Carbonate)**:
- When ammonium carbonate (NH₄O₂CO₃) is heated, it decomposes to produce ammonia (NH₃), carbon dioxide (CO₂), and water (H₂O).
- **Conclusion**: Ammonia (NH₃) **is** produced in this reaction.

6. **Evaluate Heating of NH₄NO₃ with NaOH**:
- When ammonium nitrate (NH₄NO₃) reacts with sodium hydroxide (NaOH), it produces sodium nitrate (NaNO₃), water (H₂O), and ammonia (NH₃).
- **Conclusion**: Ammonia (NH₃) **is** produced in this reaction.

7. **Evaluate Reaction of AlN (Aluminum Nitride) with Water**:
- When aluminum nitride (AlN) reacts with water, it produces aluminum hydroxide (Al(OH)₃) and ammonia (NH₃).
- **Conclusion**: Ammonia (NH₃) **is** produced in this reaction.

8. **Evaluate Reaction of Mg₃N₂ (Magnesium Nitride) with Water**:
- When magnesium nitride (Mg₃N₂) reacts with water, it produces magnesium hydroxide (Mg(OH)₂) and ammonia (NH₃).
- **Conclusion**: Ammonia (NH₃) **is** produced in this reaction.

9. **Evaluate Reaction of Ca₃N₂ (Calcium Nitride) with Water**:
- When calcium nitride (Ca₃N₂) reacts with water, it produces calcium carbonate (CaCO₃) and ammonia (NH₃).
- **Conclusion**: Ammonia (NH₃) **is** produced in this reaction.

### Final Conclusion:
From the evaluations, we find that ammonia (NH₃) is not produced in the heating of NH₄NO₃ or NH₄NO₂. Therefore, the correct answer to the question "NH₃ can't be obtained by:" is:

**Heating of NH₄NO₃ or NH₄NO₂.**