Water of crystallization is a fixed amount of water present in the crystals of compounds.

Answer

**Step-by-Step Solution:**

1. **Understanding Water of Crystallization:**
- Water of crystallization refers to the water molecules that are chemically bound within the crystalline structure of a compound. This water is essential for maintaining the structure and stability of the crystal.

2. **Definition:**
- The statement "Water of crystallization is a fixed amount of water present in the crystals of a compound" is true. This means that each crystalline compound has a specific number of water molecules associated with it.

3. **Examples of Compounds with Water of Crystallization:**
- **Blue Vitriol (Copper(II) Sulfate):** The chemical formula is CuSO4·5H2O, indicating that there are 5 moles of water of crystallization in each formula unit.
- **Green Vitriol (Iron(II) Sulfate):** The formula is FeSO4·7H2O, which shows that it contains 7 moles of water of crystallization.
- **Barium Chloride:** The formula BaCl2·2H2O indicates that there are 2 moles of water of crystallization.
- **Potash Alum:** The formula is K2SO4·Al2(SO4)3·24H2O, which contains 24 moles of water of crystallization.

4. **Conclusion:**
- Since different compounds have specific amounts of water of crystallization, the original statement is confirmed to be correct.

5. **Final Answer:**
- The statement "Water of crystallization is a fixed amount of water present in the crystals of a compound" is indeed true.

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