Hidrátok

Hidrátok are chemical compounds that contain water molecules within their crystal structure. These water molecules are incorporated into the solid lattice of the compound in a fixed stoichiometric ratio. The presence of water of crystallization is often indicated by a dot followed by the number of water molecules in the chemical formula, for example, copper(II) sulfate pentahydrate is written as CuSO4·5H2O.

The water molecules in hydrates are typically held in the crystal lattice by relatively weak ionic or hydrogen bonds. They are not considered to be part of a chemical reaction forming the hydrate, but rather are physically trapped within the structure. Upon heating, these water molecules can be released as steam, a process known as dehydration. The resulting anhydrous compound will have different physical properties, such as color and solubility, compared to its hydrated form.

Many common inorganic salts form hydrates, including gypsum (calcium sulfate dihydrate), Epsom salts (magnesium sulfate heptahydrate), and washing soda (sodium carbonate decahydrate). The number of water molecules in a hydrate can vary, and sometimes a compound can exist in multiple hydrated forms, each with a different number of water molecules. The study of hydrates is important in various fields, including chemistry, geology, and materials science, as their properties and behavior are influenced by the presence of water of crystallization.