Chemistry Question??

Question

Mt.McKinley in Alaska has an altitude of 20,320ft. Water (enthalpy of vaporization = 40.7kJ/mole) boils at 77C atop Mt. McKinley. What is the normal atmospheric pressure at the summit? in atm

Answer 1

http://en.wikipedia.org/wiki/Clausius-Cl...

where normal boiling point is 100C (373 Kelvin) @ 1 atm

ln (P2/P1) = dH vap / R [ (1 / T1 ) - (1 / T2 )

ln (P2/1 atm ) = 40,700 J / 8.314 J per [ (1 / 373K ) - (1 / 350 )

ln (P2/1 atm ) = (4895) [ (0.00268 ) - (0.00286 )

ln (P2/1 atm ) = (4895) [ (-1.8e-4 )

ln (P2/1 atm ) = (-0.881 )

e^x on both sides

(P2/1 atm ) = 0.414

your answer is P = 0.414 atm