Distillation (distillation) - the process of cleaning fluids and separation of mixtures on a separate liquid by partial evaporation and subsequent condensation formed pair. The liquid is heated in the flask (peregonnyj a cube) to the boiling point, the pair is passed through the refrigerator where they deepen, forming a refined distillate (for example, distilled water). Fractional, or fractionated, distillation separates liquid, boiling at a different temperature. As you increase the temperature of boiling mixture change receiver and get a number of distillate fractions. Repeated distillation for a more perfect purification is called rectification. By distillation impossible to separate the azeotropic mixtures of liquids, i.e. mixtures of liquids, boiling with this external pressure at constant temperature without changing composition. An example of such a mixture is 96% aqueous solution of ethyl alcohol, which boils at a temperature 78,17 degrees. The distillation in vacuum at low temperature is used to obtain substances decompose at high temperatures (such as lactic acid). Distillation with water the raft used to separate substances, volatile together with water vapor, from non-volatile (the selection of essential oils.