Theory:

Evaporation process used to separate the substance from the solvent or to obtain concentrated solutions.
Evaporation process used to obtain thermally unstable substances by heating it to the boiling point.
 
The porcelain bowl or beaker used to carry out the evaporation process.
  
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Applying the above evaporation process, we can purify common salt from water.
 
In organic chemistry, a rotary evaporator used to separate the mixture from the solvent.
 
In the rotary evaporator, the solvent usually removed from the mixture under reduced pressure, which lowers the boiling point of the solvent and makes it much easier to evaporate. Organic solvents can easily ignite, so the mixture heated in a water bath.
 
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Picture: Rotary evaporator.
Example:
Rotary evaporator can separate the caffeine from the acetone.
Reference:
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