Phosphorus Pentoxide

Phosphorus Pentoxide
Other Names: Diphosphorus pentoxide, P₂O₅, Phosphoric anhydride
CAS Number: 1314-56-3
Sum Formula: P₄O₁₀ (commonly represented as P₂O₅)
Molar Mass: 283.89 g/mol (P₄O₁₀)
Appearance: White, crystalline, or powdery solid

Phosphorus pentoxide is a powerful dehydrating agent and desiccant, known for its ability to remove water and form phosphoric acid upon contact with moisture. It is used widely in industrial drying, chemical synthesis, and laboratory applications.

Chemical and Physical Properties
Density: 2.39 g/cm³
Melting Point: 340°C (sublimes at ~360°C)
Boiling Point: Decomposes before boiling
Solubility in Water: Violently reacts, forming phosphoric acid
Solubility in Organic Solvents: Reacts with many solvents; insoluble in non-reactive nonpolar solvents
Odor: Odorless
Stability: Hygroscopic, reacts exothermically with water

Applications
Used as a strong dehydrating agent in chemical synthesis
Applied as a drying agent for gases and organic solvents
Intermediate in the production of phosphoric acid and phosphorus compounds
Utilized in polymerization and condensation reactions
Used in laboratory processes for moisture removal

Safety

Signal Word: Danger

Hazard Statements:
H314: Causes severe skin burns and eye damage

Precautionary Statements:
P280: Wear protective gloves, protective clothing, and eye/face protection
P301+P330+P331 IF SWALLOWED: rinse mouth. Do NOT induce vomiting

P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower

P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing

P310 Immediately call a POISON CENTER/doctor

First Aid Measures
Eye Contact: Immediately flush eyes with water for at least 15 minutes. Seek emergency medical attention
Skin Contact: Remove contaminated clothing. Rinse skin thoroughly with water and seek medical help
Inhalation: Move to fresh air. Provide oxygen if breathing is difficult. Seek immediate medical assistance
Ingestion: Do not induce vomiting. Rinse mouth with water and seek urgent medical attention

Handling and Storage
Store in tightly sealed containers in a cool, dry place
Protect from moisture and humidity at all times
Use only in well-ventilated areas with proper PPE (gloves, goggles, face shield)
Avoid contact with water and incompatible materials such as strong bases