What would the delta Hvap be for a substance whose vapor pressure doubled when its temperature was raised?

Question

from 70.0 centigrade to 80 degree centigrade?

Answer 1

ln(P2/P1) = (∆Hvap/R) (1/T1 - 1/T2)

ln(2/1) = ∆Hvap / (8.314 J/K-mol) (1/343 K - 1/353 K)

Solving, ∆Hvap = 69,780 J/mol or about 70 kJ/mol.