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SAI International School
                                                  Subject-Chemistry

                                           Ch-Is Matter around us pure?
                        Topic-Distillation, fractional distillation and crystallisation
                                                    LESSON NOTE




               Distillation

               Distillation is a method for separating the component substances from a liquid mixture
               by selective evaporation and condensation.
               Principle: The difference in the boiling points is the basis of the principle of distillation. On heating the
               mixture, the more volatile liquid (having lower boiling point) is converted into vapors. On cooling, the
               vapors are converted into liquid.






















                     Used in: Production of gasoline, distilled water, xylene, alcohol, paraffin,
                       kerosene etc.


               Fractional Distillation

               Fractional Distillation is the separation of a mixture into its component parts,
               or fractions. Chemical compounds are separated by heating them to a temperature at
               which one or more fractions of the mixture will vaporize. It uses distillation to fractionate.
               Generally the component parts have boiling points that differ by less than 25 °C (45 °F)
               from each other under a pressure of one atmosphere. If the difference in boiling points
               is greater than 25 °C then simple distillation is used. The fractionating column Contains
               glass beads to increase the surface area for condensation.
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