What is the mass of 2.50 moles of oxygen gas?

What is the mass of 2.50 moles of oxygen gas?

Solution:

Oxygen gas is a diatomic element, which means its formula is O2. The molar mass of oxygen gas is: 2* 15.999g/mol (from the Periodic Table)

2.50moles * 31.999 g = 80.0 g

1mol