SEPARATION TECHNIQUES Flashcards
Insoluble solids like metals and compounds like silica can be washed with water
until all the other impurities leave them.
Washing
Washing can also be done with organic solvents when there is a mixture with
soluble impurities and insoluble compounds.
Washing
This is good for separating a soluble solid
from a liquid (a soluble substance does
dissolve, to form a solution).
Evaporation
For example, table salts can be separated from salt solution (sea water) using evaporation. Remember that it is the water that evaporates away, not the solution.
Evaporation
When the densities of two liquids that are
immiscible in one another are to be
separated this method can be used.
Decanting
Separating funnel helps to separately collect the two liquids. In case of solids, the lighter solids can be separated by decanting it in water medium when both of the solids are not soluble.
Decanting
A process that depends on
differences in the volatility (how
readily substances become gases)
of the components.
Distillation
The most volatile component vaporizes at the lowest temperature, and the vapor passes through a cooled tube (a condenser), where it condenses back into its liquid state.
Distillation
Filtration is good for separating an insoluble
solid from a liquid. (An insoluble substance is
one that does not dissolve).
Filtration
Sand, for example, can be separated from a
mixture of sand and water using filtration.
That’s because sand does not dissolve in
water.
Filtration
This is good for separating dissolved
substances that have different colors, such as
inks and plant dyes.
Chromatography
It works because some of the colored
substances dissolve in the liquid better than
others, so they travel further up the paper.
Chromatography
