1. Purification of
substances

2. Characteristics of pure
substances
 A pure substances is made up of only one
substances. It is not mixed with other
substances and does not contain impurities.
 Have fixed boiling point and freezing point
 Example: water have freezing point 0°c and
boiling point 100°c.
 But, if the water added with impurities, the
freezing point will lower than 0°c and the boiling
point will higher than 100°c.

3. Method of purification
 Purification is a process of removing
impurities from a substances.
 There are three method of
purification:
– Filtration
– Crystallisation
– Distillation

4. Filtration
 A process of separating solid from
liquid
 Example: separating sand from water.

5. Crystallisation
 A process of forming crystals from a
liquid or gas.
 Example: salt from salt solution

6. Distillation
 A process to obtain a pure liquid from
a solution of mixture.
 Used to
– Obtain pure water from a salt solution.
– Obtain pure water from a sugar solution.
– Separate a liquid from of mixture of
miscible liquids with different boiling
points.

8. Uses of various
substances