Hexahydrous

Hexahydrous refers to a substance that contains six molecules of water of crystallization per molecule of the compound. This water is chemically bound to the compound and is often released when the substance is heated. The term is derived from the Greek word "hexa" meaning six and "hydor" meaning water. Many ionic compounds can form hydrates, and their chemical formulas reflect the number of water molecules. For instance, a hexahydrous compound would be represented as "X·6H₂O", where X is the anhydrous compound. The presence of water of hydration can significantly affect the physical properties of a substance, such as its solubility, melting point, and crystal structure. When a hexahydrous compound loses its water of crystallization, it is said to be dehydrated and becomes anhydrous. Examples of substances that can exist in a hexahydrous form include certain salts like nickel(II) sulfate hexahydrous (NiSO₄·6H₂O). The exact arrangement of the water molecules within the crystal lattice can vary depending on the specific compound and can be determined through techniques like X-ray crystallography.