Mixtures
1.
What is a mixture?
A mixture is a combination of two or more substances made by mixing other substances together! A mixture
is
made
of little
bits of
each
substance mixed
together.
These
substances
can
be separated by physical methods.
Mixtures can be made of solids, liquids, gases or a combination of these.
Mixtures are classified (grouped depending on whether the substances in them are solids, liquids or gases and
on how the substances can be separated.
2. Types of mixtures
i). Suspensions
A suspension is a mixture of two substances that separate if the mixture is not stirred. These two substances
are often a solid and liquid. When they are mixed, we say that one substance is suspended in the other. An
example is rocks mixed with water.
ii). Colloids
A colloid is a mixture of two substances, where one substance is dispersed (spread out) in another substances
and the two substances will not separate easily. Either substance may be a solid, liquid or gas. A colloid is
cloudy (or opaque), so it is easy to see that it is a mixture. Milk is a colloid of different milk solids dispersed in
water. Many mixtures we use are colloids, such as hair spray, hand cream, styrofoam, cups, paints and gel
inks.
iii). Solutions
A solution is a mixture where the solid dissolves in the liquid. This means that its particles spread out so much
in the liquid that light can pass through it. This makes the mixture clear or transparent. In a solution, the liquid
is called a solvent while the substance that dissolves is called a solute.
3. Types of mixtures activity: Creating a solution, suspension and colloid
Work in pairs and discuss which (a, b or c) you could mix with water to create
I.A solution
II.A suspension
III.A colloid
Write down full sentence answers using information in the text above:
I.A
solution
can
be
made
by
mixing
____________
because_______________________________________________________________..
with
water
II.A
suspension
can
be
made
by
mixing
____________
because______________________________________________________________.
with
water
III.A
colloid
can
be
made
by
mixing
____________
because_______________________________________________________________
with
water
IV.What else could you mix to create a solution, suspension and colloid?
4. Separating Mixtures – methods
Work in pairs:
Write down the methods you would use to separate sand from water in the solution.
Make sure you describe what should be done with all the apparatus and number the steps as you would do
them
Step
1.
2.
3.
4.
5.
6.