Distinguish between the pairs of compounds:
Ammonium sulphate crystals and Sodium sulphate crystals.

Explanation

To distinguish between ammonium sulfate crystals and sodium sulfate crystals, we can analyze their chemical properties, particularly their behavior upon heating.

### Step-by-Step Solution:

1. **Chemical Formulas**:
- Ammonium sulfate has the chemical formula \( \text{(NH}_4\text{)}_2\text{SO}_4 \).
- Sodium sulfate has the chemical formula \( \text{Na}_2\text{SO}_4 \).

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