Ways to separate mixtures – Chapter 3: Matter & Its Properties
How do we separate …?
Substances in a mixture are physically combined, so processes bases on differences in physical properties are used to separate component
Numerous techniques have been developed to separate mixtures to study components
Used to separate heterogeneous mixtures composed of solids and liquids
Uses a porous barrier to separate the solid from the liquid
Liquid passes through leaving the solid in the filter paper
Used to separate homogeneous mixtures
Based on differences in boiling points of substances involved
Separation technique that results in the formation of pure solid particles from a solution containing the dissolved substance
As one substance evaporates, the dissolved substance comes out of solution and collects as crystals
Produces highly pure solids
Rocky candy is an example of this
Can be used to separate a magnetic substance from a non-magnetic substance
Separates components of a mixture based on ability of each component to be drawn across the surface of another material
Mixture is usually liquid and is usually drawn across chromatography paper
Separation occurs because various components travel at different rates
Components with strongest attraction for paper travel the slowest
Decanting is done to separate particulates from a liquid by allowing the solids to settle to the bottom of the mixture and pouring off the particle-free part of the liquid. Another method is to allow two immiscible liquids to separate and the lighter liquid is poured off.
a porous material is used to separate particles of different sizes.
method is most commonly used to effect gross separations, as of liquids from suspended crystals or other solids.
to accelerate filtration, pressure usually is applied.
a series of sieves is stacked, with the screen of largest hole size at the top