technique |
basis for separation |
apply this technique to: |
adsorption / desorption |
phase transfer to a solid surface |
liquid or gaseous mixtures that contain at least
one component that adsorbs |
chromatography |
phase transfer from a mobile mixture to a stationary
phase |
liquid or gaseous solutions that contain several
components with differing affinities for the stationary phase |
condensation |
phase separation by condensing gases in the mixture
to liquids |
gaseous mixtures containing at least one gas
with a much higher boiling point than the others |
dialysis |
phase transfer through a porous membrane that
allows some molecules to pass through, but not others |
solutions containing small molecules mixed with
very large molecules |
effusion |
gases with faster molecules flow through tiny
pinholes faster than gases with slow molecules |
gaseous mixtures containing gases with different
molecular weights |
dissolution (washing,
solvent extraction) |
soluble components can be washed away, leaving
behind insoluble components (phase transfer to a washing solvent) |
mixtures of solids with different solubilities |
electrorefining |
separate a metal from impurities by dissolving
it and then plating it onto an electrode |
solid mixtures with a metal as one component
|
filtration |
collect solid particles on a filter |
heterogeneous mixture containing a solid phase |
floatation |
dense components sink, and lighter ones float |
heterogeneous mixture with phases with different
densities |
ion exchange |
ions in the mixture bind to surfaces with oppositely
charged sites (phase transfer to an ion exchange resin) |
solutions containing ions |
precipitation |
convert solutes to an easily separated solid
form |
solutions containing a solute that can be precipitated |
scrubbing |
bubble mixture through a solution that selectively
absorbs a component (phase transfer from gas to solution) |
gaseous mixtures containing a solute that can
be selectively absorbed by a scrubbing solution |
stripping |
a gas bubbled through the mixture carries off
the most volatile components
(phase transfer from solution to gas)
|
a liquid mixture containing at least one volatile
component |
volatilization
(drying, distillation,
sublimation)
|
components with widely differing volatility can
be driven out of the mixture by heating (phase change from solid or liquid
to gas) |
a mixture containing components with differing
volatility |