PHOSPHORIC ACID
Indroduction
Phosphoric acid (H₃PO₄) is a mineral acid that finds numerous applications across various industries due to its diverse . It is an essential compound with distinctive characteristics. Here's an overview of phosphoric acid:
| CAS No. | 7664-38-2 |
Standard Specification
| H2PO4 Concentration | 85 min |
| P2O3 | 62.30 |
| Iron as Fe | 10.00 max |
| Sulphate as SO4 | 300.00 max |
| Chloride as Cl- | 15.00 max |
| Flouride as F | 100.00 max |
| Ca and Mg | 50.00 max |
| Heavy Metals as Pv (Lead) | 10.00 max |
| Arsenic as F | 1 max |
| Colour | Water White |
Chemical Properties
Phosphoric acid is a tribasic acid, meaning it can donate up to three protons (H⁺ ions) per molecule. Its chemical structure comprises one phosphorus atom, four oxygen atoms, and three hydrogen atoms. When dissolved in water, it dissociates into hydrogen ions (H⁺) and phosphate ions (H₂PO₄⁻ and HPO₄²⁻).
Physical Properties:
| Density | Its density is around 1.87 g/cm³. |
| Boiling Point | Phosphoric acid has a relatively high boiling point of about 158 °C (316 °F). |
| State | Phosphoric acid is a colorless, odorless, and syrupy liquid at room temperature. |
Production
| Wet Process | Phosphoric acid is obtained by reacting phosphate rock with sulfuric acid, resulting in calcium sulfate (gypsum) as a byproduct. This method is commonly used for producing phosphoric acid for fertilizer production. |
| Fume Process | This method involves the combustion of elemental phosphorus to produce phosphorus pentoxide (P₄O₁₀), which is then hydrated to form phosphoric acid. This process is often used to produce high-purity phosphoric acid for food and industrial applications. |
Uses
Phosphoric
acid has a wide range of applications in different sectors:
| Fertilizers | It’s a key component in the production of phosphate fertilizers, such as ammonium phosphate and superphosphate. |
| Food and Beverages | Phosphoric acid is used as an acidulant in carbonated beverages, such as colas, and in various processed foods. |
| Water Treatment | It’s used for pH adjustment in water treatment processes. |
| Metal Cleaning | Phosphoric acid is used for cleaning and rust removal from metal surfaces. |
| Dentistry | It’s used in dental treatments, such as dental etching and cleaning. |
| Medicine | Phosphoric acid is used in certain medications and dietary supplements |
| Flame Retardants | Some flame retardants are based on phosphoric acid compounds |
Buffer Solutions | Phosphoric acid is used as a buffering agent in analytical and laboratory applications. |
Corrosion Inhibition | It’s used to inhibit corrosion in some industrial processes. |
| Safety Considerations | Phosphoric acid is less corrosive compared to other mineral acids like sulfuric acid or hydrochloric acid, but it can still cause irritation to the skin, eyes, and respiratory tract. It’s important to handle it with care and follow safety protocols, including wearing appropriate protective equipment.In summary, |
Phosphoric acid is a versatile compound with applications spanning from food and beverages to agriculture, industry, and medicine. Its unique properties make it valuable in various processes, and its moderate corrosiveness underscores the importance of responsible handling and safety precautions.