Hydraatioastetta

Hydraatioastetta, often translated as degree of hydration, refers to the extent to which a substance has absorbed water. In chemistry, this concept is particularly relevant when discussing hydrated salts, which are ionic compounds that have water molecules incorporated into their crystal structure. The degree of hydration quantifies the number of water molecules associated with each formula unit of the salt. For example, copper(II) sulfate pentahydrate (CuSO₄·5H₂O) has a degree of hydration of five, meaning five water molecules are bound to each formula unit of copper(II) sulfate.

This hydration can significantly alter the physical and chemical properties of a compound. Hydrated salts often have different colors, melting points, and solubilities compared to their anhydrous counterparts. The water molecules are typically held within the crystal lattice through coordination bonds with the metal cation or through hydrogen bonding. The removal of this water, known as dehydration, can be achieved by heating or exposure to desiccating agents and results in the anhydrous form of the compound. The degree of hydration is a key characteristic that determines the properties and stability of hydrated substances.