You are given
the density of helium and neon gas mixture which is 0.1562 grams per liters at 40.2degC and 296 torr. You are required to find the mole fraction of neon in this mmixture.
c = dRT/P
c = (0.1562g/L)(0.08206 L-atm/mol-K)(40.2+273)K/296torr(1atm/760torr)
c = 10.31 g/mol
since helium is 4 g/mol
mole fraction of neon = (10.31 - 4) / 10.31 = 0.612
