fractional crystallization

If the impure compound is a mixture of two compounds whose solubility in any solvent does not differ significantly from one another, then the two compounds are separated by fractional crystallization. This is a series of repeated crystallisations. For instance when a solution c..

Fractional crystallization or fractional distillation cannot bring about resolution. This is because the enantiomorphs have identical physical properties. Some of the methods used for resolution are a) Mechanical separation b) Biochemical separation c) Salt formation ..

Best of all the methods of resolution, Pasteur was again the first to use this in 1858. The principle is - "The conversion of the active constituents of the racemic mixture into Diastereomers (salts) of another optically active or base."..

. where r , called resistivity is a property of the material and depends on temperature and pressure. Electrical resistivity of substances varies over a very wide range. Metals have low resistivity, in the range of 10 - 8 W m to 10 - 6 W m. Insulators like glass and rubber have 10 2 2 to 10 2 4 tim..