Salty Thumb wrote:
snip
If you take the molar density and multiply by the molecular weight, you
get the mass density.
02 1 mol / 2.74 L = 11.7 g/L
N2 1 mol / 2.74 L = 10.2 g/L
CO 1 mol / 2.73 L = 10.3 g/L
CO2 1 mol / 2.49 L = 17.7 g/L

As I mentioned in my previous post, I think those volume figures are
a little off.

According to my handy-dandy Pocket Ref, here are the densities (@
STP):

O2 1.4290 g/L
N2 1.2506 g/L
CO 1.2500 g/L
CO2 1.9770 g/L
Air 1.2928 g/L

Just as a sanity check, I multiplied each one of those figures by
22.4 to make sure that the product was close to the molecular mass
(they are).

R,
Tom Q.