Question

how many molecules are in 5.5 moles of oxygen gas? How many atoms are in this quantity of gas?

I used dimensional analysis and did:
5.5 mol. of oxygen x 6.02x10^23 molecules/1 mol of oxygen
I got 3.3x^24 molecules of oxygen
How do I find the # of atoms? I know that there are 2 atoms of oxygen in one molecule of oxygen gas, so do I divide my answer by 2 to get the # of atoms?

Answer 1

Right on all except what you do for atoms. You are right that each molecule oxygen contains two atoms of O so doesn't it stand to reason that O atoms will be twice O molecules.

Answer 2

that makes sense, thank you!