What is the significance of the recrystallisation process in chemistry?
Recrystallisation is used to purify a solid compound. You dissolve the compound in a hot solvent to produce a saturated solution. When it cools the solid precipitates. The theory is that as impurities are a small portion of the original they would not be saturated and so remain in solution, filtration would give a pure compound. The solvent to use depends on the compound, ideally you want one that it is fairly insoluble in at low temperatures but will dissolve in at higher temperatures, you also need to ensure that you will not be heating the mixture to a temperature that will cause the compound to react or degrade. Unless there is information in literature or data tables then it comes down to a process of trial and error. In general though you can go by a series of solvents for instance during my phd work I generally went with pertoleum ether> toluene> ethanol/methanol> acetic acid> dimethyl formamide (need to be careful with acetic acid as it can cause undesired reactions with some c
