The Difference Between Gravity and Vacuum Filtration
As a technique widely used in the lab, the filtration is the best way to remove solid impurities from an organic solution and to isolate an organic solid. We can find two types of filtration: gravity filtration and vacuum filtration.
Gravity filtration is a common method to remove solid impurities from an organic liquid. The impurity that we call in the applications could be a drying agent, an undesired side product or leftover reactant.
Vacuum filtration is used to collect a desired solid too. But compare with gravity filtration, it is much faster in the result of the solvent and air being forced through the filter paper by the application of reduced pressure. Remember, never use vacuum filtration to filter a solid from a liquid if you want to use the liquid, and the solvent boiling at about 125 degrees or lower will boil off in the vacuum flask while the pressure is reduced.