A Experiment On Separation And Purification Methods

885 WordsSep 17, 20144 Pages
This experiment introduces separation and purification methods used in research quite frequently. These methods include hot vacuum filtration and recrystallization to purify a crude sample of acetanilide containing two impurities. Recrystallization is a very common method that is used to purify solids. This process dissolves a crude solid with impurities in a mildly boiling solvent, and cooling down the mixture afterwards for crystals to reconstruct themselves in solution. This method allows impurities to separate and remain in solution as precipitate or remain uniform in solution. Solids are more soluble in hot solvents than in cold ones, allowing maximum dissolution for proper separation and subsequent crystallization to occur. After purifying the compound, the melting point is determined using the Mel-Temp technology to compare to the written melting point to see how pure the sample truly is. The proper steps of recrystallization include selecting a solvent that fits the characteristic of all the components, water in this experiment. Then, dissolving a crude sample in the chosen solvent (at or close to the solvent boiling point), forming solid in the solution as cooling takes place, using vacuum filtration to isolate the purified solid, ridding the crystals of all impurities through drying. In this experiment, recrystallization allows purification of 150 mg of crude acetanilide. Hot vacuum filtration is a process used. The process requires using a filter flask, Pasteur
Open Document