Molar mass of oxygen gas (O2)

The molar mass of oxygen gas (O2) is 31.998 g/mol.

oxygen

Step-by-step calculation

ElementAtomsAtomic massSubtotal
Oxygen × 2 15.999 = 31.998
Total31.998 g/mol

Percent composition by element

  • Oxygen 100%

Oxygen gas facts

  • Oxygen gas is a colorless, odorless gas made of two oxygen atoms, and it makes up about 21 percent of Earth's atmosphere by volume.
  • It is essential for breathing and combustion and is used in hospitals, steelmaking, welding, and rocket engines.
  • Liquid oxygen is pale blue and is attracted to a magnet because each O2 molecule has two unpaired electrons.

Try another formula

H2O NaCl CO2 C6H12O6 H2SO4 Ca(OH)2 CuSO4·5H2O C8H10N4O2

Could not read that formula

Related compounds

NaOH Sodium hydroxide H2O Water CaCO3 Calcium carbonate H2SO4 Sulfuric acid Fe2O3 Iron(III) oxide NaHCO3 Sodium bicarbonate

FAQ

What is the molar mass of O2?

The molar mass of oxygen gas (O2) is 31.998 g/mol.

How do you calculate the molar mass of O2?

Multiply the atomic mass of each element by the number of its atoms in O2, then add the results: 2 × 15.999 (O) = 31.998 g/mol.

What percentage of O2 is Oxygen?

Oxygen makes up 100% of the mass of oxygen gas (O2).