CuSO4·6H2O, commonly known as copper(II) sulfate pentahydrate, is a blue crystalline solid that consists of one copper ion, one sulfate ion, and six water molecules. It is often used in laboratories and industries for various applications, including as a fungicide, herbicide, and in the preparation of other copper compounds. This compound is highly soluble in water, forming a bright blue solution. When heated, it loses its water molecules, turning into anhydrous CuSO4, which is a white powder. The transition between these forms is often used in educational demonstrations to illustrate hydration and dehydration processes.