Pentahidrato

Pentahidrato, or pentahydrate in English, refers to a chemical compound that contains five molecules of water per formula unit within its crystalline structure. It is a specific type of hydrate, where the water of crystallization is incorporated into the solid in a fixed ratio. The five water molecules can be integral to the lattice and are released when the substance is heated, leading to the anhydrous salt, if one exists.

A well-known example is copper(II) sulfate pentahydrate, CuSO4·5H2O, a blue crystalline solid commonly used in teaching laboratories and various chemical demonstrations. Many metal salts and other compounds can crystallize as pentahydrates under suitable conditions, though not all do. The presence of water of crystallization affects properties such as color, stability, and solubility, and it can influence the material’s behavior during crystallization and drying.

Dehydration is a typical characteristic of pentahydrates; upon heating or exposure to low humidity, the five water molecules are gradually or completely removed to yield the anhydrous form if it exists. Rehydration can occur when the material is exposed to water vapor, reforming the pentahydrate.

In summary, pentahidrato denotes a compound with five water molecules per formula unit in its crystalline form, with CuSO4·5H2O as the most common illustrative example. The term is used in Spanish, Portuguese, and English to describe this specific hydration state.