<Tr> <Td_colspan="2"> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> In chemistry, recrystallization is a technique used to purify chemicals . By dissolving both impurities and a compound in an appropriate solvent, either the desired compound or impurities can be removed from the solution, leaving the other behind . It is named for the crystals often formed when the compound precipitates out . Alternatively, recrystallization can refer to the natural growth of larger ice crystals at the expense of smaller ones . </P> <P> In chemistry, recrystallization is a procedure for purifying compounds . The most typical situation is that a desired "compound A" is contaminated by a small amount of "impurity B". There are various methods of purification that may be attempted (see Separation process), recrystallization being one of them . There are also different recrystallization techniques that can be used such as: </P>

Why would a recrystallization need to be done