Let's analyze each option in terms of whether it contains water of crystallization or is associated with water molecules: Cryolite ( Na3AlF6 ) → This compound does not contain water molecules. It is anhydrous (no water of crystallization). ✓ Not associated with water molecules. Bauxite (Al2O3⋅×H2O) → This is a hydrated form of alumina, i.e. it does contain water molecules. - Associated with water. Kernite (Na2B4O7⋅4H2O) → This is hydrated sodium borate, contains crystallization water. - Associated with water. Borax (Na2B4O7⋅10H2O ) → This also contains crystal water. - Associated with water. Correct Answer: Option A - Cryolite Reason: Cryolite (Na3AlF6) is not associated with water molecules.