How many molecules of oxygen gas are present in a 0.108 g sample of oxygen gas?

Answer 1

Mass of a sample of O₂: 0.108 grams

Molar Mass of O₂: 2(16.0) = 32.0 grams

Molecules of O₂: 6.02×10²³ (Avogadro's Number)

Molecules of a sample of O₂: ????

0.108 g O₂ × (1 mol O₂ / 32.0 g O₂) × (6.02×10²³ molecules O₂ / 1 mol O₂) = 2.03×10²¹ molecules O₂

There are about 2.03×10²¹ molecules of oxygen gas in a sample of 0.108 grams of oxygen gas.