CuCl2·2H2O, also known as copper(II) chloride dihydrate, is a chemical compound composed of copper, chlorine, and water. It appears as blue-green crystals and is commonly used in various applications, including as a catalyst in chemical reactions and in the production of pigments. This compound is soluble in water, forming a blue solution, and is often utilized in laboratories and industrial processes. CuCl2·2H2O can also be used in the preservation of wood and as a reagent in organic synthesis, showcasing its versatility in both scientific and practical uses.