CuSO4·8H2O, commonly known as copper(II) sulfate pentahydrate, is a blue crystalline solid that consists of copper, sulfur, and oxygen, along with water molecules. It is often used in laboratories and industries for various applications, including as a fungicide, herbicide, and in the production of other copper compounds. This compound is notable for its vibrant blue color, which is due to the presence of copper ions. When heated, CuSO4·8H2O loses its water molecules and turns into anhydrous copper(II) sulfate, which is a white powder. Its chemical formula indicates that each formula unit contains eight water molecules, contributing to its hydrated form.