A certain substance has a heat of vaporization of 65.34 kJ/mol. At what Kelvin temperature will the vapor pressure be 4.00 times higher than it was at 299K?

Answer 1

Clausius Clapeyron equation: ln (P2/P1) = -∆Hvap/R (1/T2 - 1/T1)

P1 = P1

P2 = 4P1

∆Hvap = 65.34 kJ/mol

R = 8.314 J/Kmol = 0.008314 kJ/Kmol

T1 = 299

T2 = ?

ln(4P1/P1) = - 65.34 kJ/mol/0.008314 kJ/molK (1/T2 - 1/299)

1.386 = -7859 (1/T2 - 0.0033)

1.386 = -7859/T2 + 26.28

-24.90 = -7859/T2

T2 = 316K