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Secondary I • 1yr.


I learned about separating mixtures methods in class (evaporation, decantation, filtration, distillation, sieving, centrifugation, paper chromatography, and chemical techniques), but I'm not sure that I use the right technique in the right situation. 

Can you explain to me, please?


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Explanations (1)

  • Explanation from Alloprof

    Explanation from Alloprof

    This Explanation was submitted by a member of the Alloprof team.

    Team Alloprof • 1yr.


    First, you can use evaporation with a solution where there is a liquid substance and a solute. Evaporation will transform the liquid into gas, and therefore concentrate the remaining solution in the container.

    Decantation can be used to separate immiscible liquids that don't have the same density. When the phases are well separated, one can only remove one of the substances with a separatory funnel.

    Filtration can be used to separate a solution where there is a liquid substance and a solid substance. Using a filter will create a filtrate and a residue.

    The distillation can be used to separate two liquids of a homogeneous solution. The different boiling points of the different substances cause the evaporation of one of the two substances making the distillate collection possible.

    Sieving can be used to separate solids. A sieve is used for this method.

    Centrifugation can separate a homogeneous mixture in several stages with the aid of centrifugal force allowing particles to be divided by their mass. The different phases created can therefore be collected separately afterward.

    The paper chromatography allows determining the different components of a substance by their characteristic migration speed. As each component has a different attraction with the solvent in which the paper is immersed, it will be possible to distinguish the distinct substances present by their position on the paper.

    One of the chemical techniques is precipitation, in which another substance is added to the mixture studied to cause the appearance of a precipitate, making it possible to verify the presence of certain ions in the solution.

    I hope this enlightens your understanding! 

    Don't hesitate to ask other questions!