Why does water evaporate on heating while oil doesn’t?
Evaporation Of Water, Oil Does Not
Evaporation happens at room temperature. When we heat something, boiling and vaporization happen.
Vegetable oils, when heated, start producing smoke first. The smoke is nothing but the oil molecules’ game vaporized or getting decomposed and then vaporized. If we continue hearing it further, the oil will reach its auto ignition temperature and will catch fire.
– Written By SHRUTI SINGH
All liquids ultimately boil at some temperature. The vegetable oils are not easy to evaporate because of high molecular weights and, more than that, the presence of the highly polar triester glyceride functional group. The glyceride ester function renders the oils vulnerable to decomposition at high temperatures, before the oil gets any chance to evaporate, under atmospheric pressure and open to the surroundings, which would lead to oxidation and oxidative decomposition of the molecules. However, if you want, you may distill oils under reduced pressure.
– Written By SHRUTI SINGH
