posted by rachel .
the mass of the oxygen (o2) in a room is 0.0568 grams. How many oxygen molecules are in the room. 2 conversions are needed.
mols O2 = grams/molar mass
# molecules = mols O2 x 6.02E23 or if you want to do conversions; do it this way.
0.0568g O2 x (1 mol O2/32 g O2) x (6.02E23 molecules/1 mol O2) = ? molecules O2.