A dihydrate is a chemical compound that contains two molecules of water (H₂O) for each formula unit of the substance. This water is often integrated into the crystal structure of the compound, influencing its physical properties, such as solubility and stability. Common examples of dihydrates include copper(II) sulfate dihydrate and calcium sulfate dihydrate. In many cases, dihydrates can lose their water molecules when heated, transforming into an anhydrous form. This process is important in various applications, including pharmaceuticals and construction materials, where the presence or absence of water can significantly affect the material's performance and usability.