Phosphoric Acid English Name: Phosphoric acid Also Known As: Orthophosphoric acid Chemical Formula: H?PO? Molecular Weight: 98 CAS Registry Number: 7664-38-2 EINECS Number: 231-633-2 Melting Point: 42?°C Boiling Point: 261?°C Density: 1.874?g/mL Appearance: Transparent colorless liquid Water Solubility: Miscible with water in any ratio Applications: 1. Agriculture: Phosphoric acid is a raw material for producing important phosphate fertilizers (such as calcium superphosphate and potassium dihydrogen phosphate), as well as feed nutritional supplements (e.g., calcium dihydrogen phosphate). 2. Industry: Phosphoric acid is a significant chemical raw material with the following main uses: - Treating metal surfaces to form insoluble phosphate films that protect metals from corrosion. - Mixed with nitric acid as a chemical polishing agent to improve the smoothness of metal surfaces. - Serving as a raw material for producing phosphate esters used in detergents and pesticides. - Used in the production of phosphorus-containing flame retardants. 3. Food: Phosphoric acid is a food additive, functioning as an acidulant and yeast nutrient. It is found in beverages such as cola. Phosphates are also important food additives, acting as nutritional enhancers. 4. Medicine: Phosphoric acid is used in the preparation of phosphorus-containing drugs, such as sodium glycerophosphate.