Hidráltság

Hidráltság refers to the presence of water molecules within a chemical compound. These water molecules are not simply absorbed or adsorbed on the surface but are chemically bound to the ions or molecules of the substance. Compounds that contain these chemically bound water molecules are called hydrates. The number of water molecules associated with each formula unit of the compound is indicated by a raised dot followed by the number of water molecules, such as in copper(II) sulfate pentahydrate, CuSO4·5H2O.

The water molecules in a hydrate are typically incorporated into the crystal lattice structure of the compound. The process of forming a hydrate is called hydration. Conversely, the removal of these bound water molecules is known as dehydration or efflorescence. Dehydration can often be achieved by heating the hydrate. For example, heating copper(II) sulfate pentahydrate will remove the water molecules, leaving behind anhydrous copper(II) sulfate.

Hydrates are common in inorganic chemistry and can have different properties compared to their anhydrous counterparts. For instance, the color, solubility, and melting point can be affected by the presence of water of hydration. Some substances readily form hydrates when exposed to atmospheric moisture, a phenomenon known as hygroscopy. Understanding hidráltság is important in various fields, including chemistry, geology, and materials science, as it influences the behavior and applications of many substances.