What is hepta-hydrate?

A hepta-hydrate is a type of hydrate that contains seven water molecules (H₂O) for each formula unit of a compound. In chemical notation, it is often represented by the suffix "·7H₂O." Hepta-hydrates are commonly found in various salts and minerals, where the water molecules are integrated into the crystalline structure, influencing the compound's physical properties. An example is copper(II) sulfate heptahydrate, which is a blue crystalline solid used in various applications.