If 191g of the vapor of a volatile liquid is able to fill a

If 1.91g of the vapor of a volatile liquid is able to fill a 408-mL flask at 100.4C and 765mm Hg, what is the molar mass of the liquid? What is the density of the vapor under these conditions?

Solution

P = 765/760 = 1.006 atm

V = 0.408 L

T = 373.4K

R = 0.082

m = 1.91g

PV = (m/M)RT

M = 142.48gm

density = mass/volume = 1.91/0.408 = 4.68gm/L