CuSO4·5H2O, commonly known as copper(II) sulfate pentahydrate, is a blue crystalline solid that consists of copper sulfate and five 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 easily soluble in water, forming a bright blue solution. When heated, it loses its water of crystallization, turning into anhydrous CuSO4, which is a white powder. The pentahydrate form is frequently used in educational settings to demonstrate chemical reactions and properties of hydrates.