Separating chemical compounds, mixtures

Sometimes we have to separate a chemical compound from a mixture. We use different physical characteristics such as boiling point, polarity of compounds to separate chemical compounds from mixtures. But sometime we cannot obtain 100% pure compound after separating.

Examples of separating chemical mixtures

Removing water from a solid is also an example to separating compounds.

Separating of mixtures

Transferring of materials from one homogeneous phase to another is defined as separating of mixtures.

Petroleum Refining

Petroleum is a complex mixture of alkanes, cyclo alkane and aromatic compounds. Crude oil is not worth until it is separated into different compounds such as petrol, diesel, kerosene and many more.

Crude oil contains thousands of compounds. Composition of crude oil is classified according to their range of boiling points. These hydrocarbons are separated on the basis of their molecular mass by fractional distillation.

Advantages of separating compounds

Recover valuable materials

Valuable materials may be mixed with dirt or waste. But we need to recover or separate that valuable material. Therefore we have to follow a specific separating method to recover that material from initial mixture.

Economical advantages

Removing unwanted materials from a mixture will reduce the weight of mixtures. It is very important in transporting. So reducing weight will decrease the cost of transportation.

Separating methods of chemical compounds

  • Distillation
  • Crystallization
  • Centrifugal Separations
  • Evaporation
  • Absorption
  • Adsorption
  • Drying
  • Chromatographic Separations
  • Liquid - liquid Extraction

Mechanical separating methods of chemical compounds

  • Cyclone separator - used in cement manufacturing process plants
  • Filter press
  • Gravity settlers

What physical properties are used in separating chemical compounds?

  • Vapor presssure
  • solubility / diffusivity
  • volatility
  • concentration differences

Boiling point

In distillation, boiling point is used to separate chemical compounds. The most industrial use of this is, petroleum refining process. Petroleum contains so many organic chemicals and they have boiling point values.


Some compounds dissolve very well in some solvents than another solvent.

Related tutorials to chlorination of alkanes

Alkane preparing, reactions Alkyl halides preparing, reactions Grignard reagent Organic conversions questions