From the Daily Post
As a student studying chemistry, I can tell you exactly what happiness looks like. From all my research and lab courses, happiness is a good yield, a TLC plate with few spots, an NMR spectrum without unexplainable peaks, an IR spectrum with no unexpected -OH bands, and a purification technique that was successful! One of the most common purification techniques used in an organic lab is recrystallization of the product. For instance, when synthesizing benzil from benzaldehyde, it is appropriate to use boiling ethanol to dissolve all the crude benzil to produce a saturated solution. As the solution cools, the desired product becomes less soluble in solution and crystalizes. Ideally, the impurity will remain in solution, or only very little will co-precipitate. If this process is repeated, the purity will increase as more impurity is isolated from the target product.
Benzil – Before Recrystallization
Benzil – After recrystallization