posted by Bobby on .
one mole of a gas occupies 27.0 liters, and its density is 1.41g/l at a particular temperature and pressure. what is its molecular weight? What is the density at STP?
The molar mass of a gas is the mass of a mole. Since the density is 1.41 g/L and the volume of 1 mole at the listed T and P is 27 L; therefore, the mole has a mass of
1.41 g/L x 27 L = about 38. Check me out on this and round to three significant figures. Since a mole of a gas at STP occupies 22.4 L, then 38/22.4 = ?? density at STP (substitute YOUR value for the 38 in the latter). I find approximately 1.7 g/L. Again, round to 3 s.f.