Vapor Pressure of a certain liquid

Question

A certain liquid has a vapor pressure of 92.0 Torr at 23.0 ∘C and 206.0 Torr at 45.0 ∘C.

a. Calculate the value of delta H vap for this liquid.

b. Calculate the normal boiling point of this liquid.

Answer 1

Clausius Clapeyron equation:

ln (P2/P1) = -∆Hvap/R (1/T2 - 1/T1)

P1 = 92.0 torr

P2 = 206 torr

R = 8.314 J/mol-K = 0.008314 kJ/Kmol

T1 = 23.0ºC + 273 = 296K

T2 = 45ºC + 273 = 318K

∆Hvap = ?

ln (206/92) = - ∆Hvap/0.008314 (1/318 - 1/296)

0.806 = ∆Hvap / 0.008314 (0.00314 - 0.00338) = ∆Hvap/0.008314 (-0.00024)

∆Hvap = 27.9 kJ/mol

(be sure to check my math)