2. Separation of Mixtures
Identify the different ways of separating
mixtures.
Determine how the different ways are used to
separate mixtures.
Identify the ways in which Hand Picking,
Threshing, Winnowing, Sieving, Magnetic
Attraction, Sublimation, Evaporation,
Crystallization, Sedimentation & Decantation,
Loading, Filtration, Distillation, Centrifugation,
and Paper Chromatography can be used in
daily life.
3. A Mixture….
o consists of two or more different
substances that are mixed but not
chemically combined.
o they do not have well defined specific
properties.
o can be separated into its components by
physical means.
4. Rock-mixture of
different kinds of rocks
Sandwich-
mixture of bread,
meat, tomato
Examples of Mixtures
Soda- mixture of
sugar and water
5. 2 Types of Mixtures
The prefixes:
“hetero” indicate
difference.
A heterogeneous
mixture is that
which does not
have the same
composition
throughout, that is,
its components are
not uniformly
distributed and can
be distinguished
from each other.
6. oExamples:
•Concrete
•Beach sand is heterogeneous
since you can see different
colored particles
•Vinegar and oil salad dressing is
heterogeneous since two
liquid layers are present, as
well as solids.
7. The prefixes:
“homo” indicate
sameness.
A homogeneous
mixture is that
which has the same
composition
throughout, that is,
its components are
uniformly distributed
and cannot be
distinguished from
each other.
11. The components of a solid-solid mixture
can be separated by hand picking.
This is only useful when the particles are
large enough to be seen clearly.
For example
• separating pebbles from rice or dal,
• separating grass from mint leaves, and
• separating parts of a salad.
13. Threshing is the method that generally
used by the farmers to separate the
grains from the stalks after harvesting.
The dried stalks are beaten or threshed
to separate the grains.
However, in large farms threshing is
done by using threshing machines.
15. In Winnowing the mixture is allowed to
fall from a height.
The lighten components get separated
from the heavier ones because of wind
or air blow.
This method is used to separate lighter
husk from heavier Grains like wheat.
16. Sifting or Sieving
Sieving is used to separate a dry mixture
which contains substances of different sizes
by passing it through a sieve.
17. A sieve is a device containing tiny holes
and separates wanted elements from
unwanted material.
18. Magnetic Attraction or Magnetism
Magnetism is
a process in
which
magnetically
susceptible
material is
extracted
from a
mixture
using a
magnetic
force.
20. oExample
Iodine and ammonium chloride
On heating, they do not melt.
Iodine changes into a beautiful violet
vapor while ammonium chloride changes
into a white vapor.
They change back into solid crystal on
cooling.
21. Evaporation
Evaporation is a process in which a liquid
changes into gaseous form on heating.
Allowing the liquid to evaporate, leaving
the soluble solid behind.
22. Crystallization is a process which separates
a pure solid in the form of its crystals
from a saturated solution.
Crystallization
23. Sedimentation and Decantation
Sedimentation is the process by which the
insoluble, heavy solid particles settle down their
own in a solution. In order to separate the two,
the liquid has to be gently poured into another
24. container without disturbing the sediments.
This process of obtaining clear liquid by pouring a
solution from a container in order to leave the
sediments in the bottom of the original container
is called decantation.
25. Loading
Loading is a process which speeds up the
sedimentation. In fact, loading is a faster
process as compared to sedimentation.
27. Filtration is commonly the mechanical or
physical operation which is used for the
separation of solids from fluids (liquids or
gases) by interposing a medium through
which only the fluid can pass.
oExample:
Using a coffee filter to
separate the coffee
flavor from the coffee
beans.
28. Distillation the process by which a mixture
is separated by heating a solution and
condensing using a cooling tube.
The liquid collected is the distillate.
Distillation
29. “It is the process whereby distilled water is
produced and accessible in the market”
“Rain water is a product of distillation”
“Some medicine that has fish oil ingredients
passes through double distillation”.
Gasoline, kerosene, fuel oil, and lubricating
oil are produced from petroleum by
distillation.
32. No chemical change occurs when salt
water is distilled.
Saltwater solution
(homogeneous mixture)
Pure water
33.
34. Centrifugation
• Spin sample very rapidly: denser
materials go to bottom (outside)
• Separate blood into serum and plasma
-Plasma = less dense
-Erythrocytes = red blood cells
• Check for anemia (lack of iron)
39. Review Questions
Exercise 1
Consists of two or more different
substances that are mixed but not
chemically combined.
a. mixture
b. compound
c. substance
d. solution
41. Exercise 2
A ____________________ is that which does not
have the same composition throughout,
that is, its components are not uniformly
distributed and can be distinguished from
each other.
a. mixture
b. compound
c. heterogeneous mixture
d. homogeneous mixture
43. Exercise 3
A ____________________ is that which has the
same composition throughout, that is, its
components are uniformly distributed and
cannot be distinguished from each other.
a. mixture
b. compound
c. heterogeneous mixture
d. homogeneous mixture
47. Exercise 5
This is a process in which magnetically
susceptible material is extracted from a
mixture using a magnetic force.
a. sieving
b. filtration
c. paper chromatography
d. magnetic attraction
49. Exercise 6 (answer each question)
Question 1
Why is a chocolate chip cookie considered
a mixture?
50. Answer Exercise 6
1. Chocolate chip cookie
o They are mixtures because they are made
up of 2 different substances mixed together
(cookie and chocolate chips).
o The individual parts keep their original
properties.
o The parts can be separated easily by
physical means.
