Here's why:
* Water of crystallization is water molecules that are incorporated into the crystal structure of a compound.
* These water molecules are chemically bound to the compound and contribute to its overall mass.
* Molar mass is the mass of one mole of a substance. It includes the mass of all the atoms in the compound, including the water of crystallization.
Example:
* Copper(II) sulfate pentahydrate (CuSO₄·5H₂O) has five water molecules per formula unit.
* To calculate its molar mass, you must include the mass of those water molecules along with the mass of the copper, sulfur, and oxygen atoms.
Let me know if you'd like a specific example worked out!
