DioxygenO₂

O2 • 31.998 g·mol⁻¹

molecularcovalentgasCAS 7782-44-7PubChem 977 →
O₂O231.9980 g·mol⁻¹
Molar mass31.998 g·mol⁻¹calc 31.998 • Atomic weights: CIAAW 2021 (conventional atomic weights)
FormulaO₂O2
Classmolecular • covalentgas
Composition — O₂
ElementCountMass (g/mol)Mass %
O231.998100.00%

Physical properties

State at STP
gas
Density
0.001429 g·cm⁻³ (gas at STP)
Melting point
54.36 K (1 atm)
Boiling point
90.2 K (1 atm)

Structure & bonding

Paramagnetic double-bonded O2 with two unpaired electrons. Strong oxidizing agent.

Occurrence & preparation

21% of air. Industrial fractional distillation of liquid air.

Uses

  • Respiration support (regulated)
  • Steelmaking

Safety

Oxidizer — supports combustion.

Consult current SDS. — consult current SDS before handling.

Constituent elements

Related reactions

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