Predicting Relative Equilibrium Vapor
Pressures and Boiling Point Temperatures:
Consider the following pairs of molecules. Which substance in each pair would you expect to have the higher equilibrium vapor pressure (at equal temperatures), and which do you think would have the higher normal boiling point?
a. Glycerol has many uses, including the production of nitroglycerine for dynamite. It is also used as a moistening agent for cosmetics and tobacco. Ethyl acetate, a compound with a pleasant smell, is added to synthetic food essences.
b. Both diethylene glycol, HOCH2CH2OCH2CH2OH, and chloroform, CH3Cl, are potentially poisonous. Diethylene glycol causes liver damage, and yet in 1985, a European winemaker was discovered to have added it to wine to increase the sweetness. Chloroform, CHCl3, is a suspected carcinogen formed in minute amounts when chlorine is used to purify water.