CuSO45H2O

CuSO45H2O, more commonly written CuSO4·5H2O and known as copper(II) sulfate pentahydrate, is the hydrated form of copper sulfate. It is a blue crystalline solid composed of copper(II) ions, sulfate counterions, and five water molecules that are part of the crystal structure. The compound is highly soluble in water, forming blue solutions, and is a widely used inorganic salt in industry, laboratories, and education.

Production and occurrence: Copper sulfate pentahydrate is produced commercially by leaching copper-containing ore with sulfuric acid to form a copper sulfate solution, from which crystals of CuSO4·5H2O are produced by evaporation and cooling. It can also be prepared by dissolving copper metal or copper oxide in sulfuric acid and crystallizing the pentahydrate. The solid is often referred to by the common name blue vitriol.

Properties and reactions: CuSO4·5H2O is blue and hygroscopic, readily absorbing moisture from the air to maintain its hydrated form. On heating, it loses its water of crystallization and gradually forms less hydrated forms, ultimately yielding anhydrous copper sulfate (CuSO4). The dehydration is reversible: exposure to water or humidity regenerates the blue pentahydrate.

Applications: The pentahydrate is used as a laboratory reagent and as a source of copper in various chemical syntheses. In agriculture and water treatment, copper sulfate serves as a fungicide and algaecide and is a component of Bordeaux mixtures used to control plant diseases. It also finds use in electroplating, textile dyeing, and qualitative inorganic analysis.

Safety: Copper sulfate is toxic if ingested and can cause irritation to skin and eyes. It is hazardous to aquatic life and should be handled with appropriate protective equipment and disposed of according to local regulations.