Homogeneous mixtures are more difficult to separate, special separation methods are needed, such as distillation simple and fractional, both consist of heating the mixture to boiling and then condensing the vapors of the liquid.
Simple Distillation: It is a process used to separate a solid and a liquid from a homogeneous mixture. It consists of separating the liquid in the form of vapor and this vapor is then condensed through a device called a condenser. The condenser has a distillation flask where the mixture is heated, the vapors produced by this heating pass through the condenser where they are cooled and transformed into liquid again through the process of liquefaction. The solid part of the mixture does not evaporate as it is not volatile and thus remains in the distillation flask.
Fractional Distillation: The fractional distillation process comprises heating a mixture of more than two liquids that have boiling points not very close. Thus, the solution is heated and initially the liquid with the lowest boiling point is separated. Then, the solution is heated until separating the liquid with the boiling point above the first separated liquid, and so on, until separation of the liquid with the highest boiling point.
Examples:
- Fractional distillation is used, for example, in petrochemical industries to separate the various petroleum derivatives, where each component is distilled at a different temperature.
- Another example of this process is seen in the stills, where alcohol is removed from the must (garapa) of the sugarcane. This must is sugarcane juice that undergoes a process of decomposition by microorganisms called fermentation.
By Líria Alves
Graduated in Chemistry
Source: Brazil School - https://brasilescola.uol.com.br/quimica/separacao-misturas-homogeneas.htm