This document discusses methods for separating and purifying mixtures. Section 3.4 focuses on separating a liquid solvent from an aqueous solution using simple distillation. Simple distillation involves boiling the solution so that the solvent, having a lower boiling point than the solute, vaporizes and condenses as a pure liquid distillate. For example, water can be separated from a sugar solution or potassium bromide solution by heating the mixture to vaporize the water, which is then cooled and collected as pure distillate, leaving behind a more concentrated solution of the solute.

1. CHAPTER 3
Separation and Purification
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2. 3.1 Obtaining Pure Substances from Mixtures
3.2 Separating a Solid from a Liquid
3.3 Separating Solids
3.4 Separating a Liquid (Solvent) from An Aqueous
Solution
3.5 Separating Liquids
3.6 Chromatography
3.7 Determining Purity
Separation and PurificationChapter 3
2

3. Learning Outcome
• describe a method to separate and purify a
solvent from a solution.
At the end of this section, you should be able to:
3.4 Separating a Liquid (Solvent)
from a Solution
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4. Recall from Chap 4:
Aqeuous Solutions are Mixtures.
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3.4 Separating a Liquid (Solvent)
from a Solution
SOLUTE

5. Simple Distillation
Simple distillation is used to separate a pure
solvent (liquid) from a solution.
Examples:
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3.4 Separating a Liquid (Solvent)
from a Solution
Mixture (Aqueous
Solutions)
Soluble Solid (Solute) Liquid (Solvent)
Sugar solution Sugar (any solute) Water (the solvent)
Aqueous
potassium bromide
Potassium bromide
(Ionic Compound)
Water (the solvent)

6. Setting Up the Distillation Apparatus
Thermometer
bulb should be
just beside the
side arm
leading to the
condenser.
Water enters the
condenser from the
bottom and leaves
from the top.
Condenser must be
sloping downwards.
Boiling chips
are placed in
the flask to
ensure smooth
boiling.
Volatile liquids can be kept in the
liquid state by placing receiver on ice.
water in
water out
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3.4 Separating a Liquid (Solvent)
from a Solution

7. Simple distillation of salt solution
2. Water boils and becomes
vapour. Thermometer measures
temperature of the vapour.
3. Water vapour
is cooled and
condenses into
pure liquid
(distillate).
5. Pure water
is collected
as distillate.
4. The salt solution
becomes more
concentrated as
distillation
continues. Salt will
be collected as
residue.
1. Boiling chips
are added to
ensure smooth
boiling. Water
vaporises, rises
and enters the
condenser. 7
3.4 Separating a Liquid (Solvent)
from a Solution