Vapor Pressure Diethyl Ether

Calculate the heat of vapourization of diethyl ether (C4H10O) from vapour pressures of….?

410 torr @ 18 degrees C and
760 torr @ 35 degrees C

Clausius – Clapeyron Relation:
ln(p1/p2) = (∆Hv/R) (1/T1 – 1/T2)
Just substitute:
ln(410 torr / 760 torr) = (∆Hv / 8.314 J/K*mole) (1/291.15 K – 1/308.15 K)
Solving, ∆Hv = 23,672 J/mole (or about 23.7 kJ/mole).