Phosphorus Pentoxide (P₂O₅)

Phosphorus Pentoxide (P₂O₅)Phosphorus pentoxide (P₂O₅), also known by its molecular formula P₄O₁₀, is a white, crystalline inorganic compound that serves as one of the most powerful desiccants and dehydrating agents available.

Despite its common name suggesting the formula P₂O₅, the actual molecular structure consists of P₄O₁₀ dimers.260203-ph


Key Properties

Physical Characteristics:

  • Appearance: White, odorless crystalline powder or granules
  • Molecular weight: 283.89 g/mol (for P₄O₁₀)
  • Melting point: 340°C (sublimes at 359°C)
  • Highly hygroscopic nature

Chemical Properties:

  • Extremely strong affinity for water
  • Reacts vigorously and exothermically with water to form phosphoric acid
  • Acts as a powerful oxidizing and dehydrating agent

Primary Applications

Industrial Uses:

  • Desiccant: Widely used in laboratories and industrial processes to remove moisture from gases and liquids
  • Chemical synthesis: Dehydrating agent in organic chemistry reactions
  • Phosphoric acid production: Raw material for manufacturing various grades of phosphoric acid
  • Semiconductor industry: Used in specialized manufacturing processes

Research and Laboratory:

  • Drying agent for solvents and chemicals
  • Catalyst in certain organic reactions
  • Analytical chemistry applications

Safety Considerations

Phosphorus pentoxide requires careful handling due to its reactive nature:

  • Corrosive to skin, eyes, and respiratory tract
  • Reacts violently with water, generating significant heat
  • Requires storage in airtight containers away from moisture
  • Personal protective equipment essential during handling

Storage and Handling

Store in tightly sealed containers in cool, dry environments, away from water sources and incompatible materials such as strong bases and reducing agents.

Phosphorus Pentoxide

Product Phosphorus Pentoxide
Synonyms Phosphorus Oxide; Phosphoric Anhydride; Phosphorus pentaoxide
Formula P2O5
CAS No. 1314-56-3
Molecular Weight 141.94