Mixtures of Ideal Gases Quiz

1
Mixtures of Ideal Gases Quiz 1 Assume the
atmosphere in Butte is 80.0 by volume N2 with
the rest being O2. Calculate the density in
g/liter of air in Butte when the temperature is
25.2 ?C and the barometric pressure is 619.7 mm
Hg. 1st calculate the mole fractions using
Amagats law, for which volume fractions are mole
fractions for ideal gases XN2 VN2 / Vtotal
0.800 XO2 1.00 0.800 0.200 Next
calculate the average molecular weight
Mavg XN2 MN2 XO2 MO2 (0.800) (28.02
g/mol) (0.200) (32.00 g/mol) 28.82
g/mol Finally calculate the density of this ideal
gas mixture ? Ptotal Mavg / ( R T
) (619.7 mm Hg) ( 1 atm / 760 mm Hg)
(28.82 g/mol) -------------------------------
-----------------------------------
(0.08205 L atm / (mol K)) (298.4 K) 0.960
g / L