Question

if the vapor pressures of hexane and heptane are 787 and 302 torr at 343 K, the mole fraction of hexane in the vapor phase exceeds 40% when the mole fraction of heptane in the liquid phase is 60%...t/f

Answer 1

From the given data,

Аишах.- Giuen, * it tu vapour prenures of heraue and lieplane are 781 and 202 torr at 843k. *ru mode fraction of heraue in the vapor phase exceeds 401 allen tue mole fraction of leptane in the liquid phase is 60% We now that, Raoult's low for vapour liquid equilibxium ; P2P, Satar + P2 sata allen, Pas total pressure peat is saturation vapour pressure of component 1 in the liquid phase Xi molefraction or component dat rapow pressure of component 2 Saturation lle D Molefraction of componunt 2 in tue liquid phase 2. lnde since we know Xe 4 X2=1

Here Juni Jaluation vapour pressure of heraue (1). Sat P = 787 torr Saturation rapour pressure at of heptane (2) esat . 302 torr Molefraction of deptane in liquid X, 50-6 Molefraction of herane in liquid x =1-12 21-06 = 0.4 So, total peresul 1 sat sat, PED + B, 2 (787x04 )+ (302 x 06) 496 torr From Raoult's low, -Y, PE p, sata, where y; - mode fraction of I' in vapor prase Bimilarly, Y, P = Pylle sata

"Y, P = 0, scaten · 4, * 496 = 181*0.4 187*0.4 => 4 - 496 -0.634 80, Molefraction of heraue in the trapour phase is 63.4% 30. tue statement, que mole fraction of bereque in the False. Vapour phone duernot erleeds 401 is