Oxalic acid is a colorless, crystalline organic compound with the chemical formula H2C2O4. It is naturally found in various plants, particularly in foods like spinach and rhubarb, and serves as a common component in some household cleaning products. Oxalic acid has versatile applications, most notably as a rust remover and stain cleaner for metal surfaces. In addition to its cleaning properties, it is used as a reducing agent in certain chemical reactions and as a mordant in textile dyeing. However, it should be handled with caution as it can be toxic when ingested in large quantities. Its ability to effectively remove stains and its role in various chemical processes make oxalic acid a valuable compound in both household and industrial settings.