Physical Chemistry

sup /sci/

The density of dry air at 1.00 atm and 34.4 degrees C is 1.15 g/L.  Calculate the composition of air (percent by mass) assuming that it contains only nitrogen and oxygen and behaves like an ideal gas.  (Hint:  First calculate the "molar mass" of air, then the mole fractions, and then the mass fractions of O2 and N2.)

I've got the first bit done.  Molar mass of air is 29.0 g/mol.  Can't figure out how to finish up.

x=%O2
y=%N2

x(mm of O2) + y(mm of N2) = 29

32x + 28y = 29
  x +   y = 1

That should get you started. Do your own fucking homework next time :)

This isn't physical chemistry.


This is grade 10 math.