- Copper sulfate, chemically known as cupric sulfate (CuSO₄), is a widely used inorganic compound that appears as a blue crystalline solid in its most common hydrated form, copper(II) sulfate pentahydrate (CuSO₄·5H₂O).
- It is highly soluble in water and forms a characteristic bright blue solution due to the presence of hydrated copper(II) ions. This compound is known for its versatility and plays significant roles in chemical, agricultural, biological, and industrial applications.
- In the laboratory, copper sulfate is frequently employed in biochemical assays, most notably in the Biuret test for protein quantification. In this context, Cu²⁺ ions react with peptide bonds in proteins under alkaline conditions, forming a violet-colored complex that can be measured spectrophotometrically. This makes copper sulfate a key reagent in protein analysis, as it facilitates the detection of polypeptides based on their chemical structure.
- Copper sulfate also finds extensive use in agriculture as a fungicide, herbicide, and pesticide. It is commonly applied to crops to prevent fungal infections such as downy mildew and is also used in Bordeaux mixture, a combination of copper sulfate and lime, to protect grapevines and other plants. Due to its antimicrobial properties, it is used to control algae and bacteria in water treatment systems and aquaculture.
- In education and chemical demonstrations, copper sulfate is used to illustrate chemical principles such as crystallization, redox reactions, and hydration-dehydration processes. When heated, the hydrated form of copper sulfate loses its water molecules and turns white (anhydrous form), a change that can be reversed by adding water, making it an effective visual aid.
- Despite its usefulness, copper sulfate can be toxic if ingested or improperly handled. It can cause irritation to the skin and eyes and is harmful to aquatic life in concentrated forms. Therefore, appropriate safety precautions and disposal practices are necessary when using this compound in laboratory or field settings.
- In summary, copper sulfate is a chemically and biologically significant compound that serves diverse roles in scientific, agricultural, and industrial contexts. Its strong reactivity, especially with proteins and microorganisms, underpins its utility in both analytical and applied sciences.
