The relationship between the vapor pressure of a liquid and temperature can be expressed by the clausius-clapeyron equation:
log[P2/P1]=deltaHvap/19.15] mol^-1K^-1]^1[1/T1/T2]
Ethanol (C2H5OH) has a normal boiling point of 78.3 celsium and with DeltaHvap=39.3KJ/mol. What is the vapor pressure of ethanol at 50.0 celsium?