Topics: Pure Substance and Mixtures

1. Pure Substances
and Mixtures
Matter and its Properties

2. • Matter can be classified into two – pure substances and
mixtures.
Pure substances
They are defined as substances that are made of only one type of
atom or only one type of molecule.
Pure substances can be classified further into elements or
compounds.
• All elements are made up of small particles called atoms. And
inside each element is a unique type of atom which is different
from the other elements.
• All compounds are made up of small particles called molecules.
If you are going to take a look inside a compound, you are going
to see only a single type of molecule, which is different from the
molecule of other compounds.

3. An element has the following characteristics:
• They consist of atoms which all have the same number of
protons.
• They are chemically the simplest substance.
• They cannot be broken down using chemical methods.
• They are made up of small particles called atoms
• Elements can be classified as metals, nonmetals or metalloids.
Examples of elements are the ones found in the periodic table –
such as oxygen, hydrogen, carbon, nitrogen, calcium, sodium,
chlorine, sulfur, tin, gold, silver and iron.

4. A compound is a substance that results from a chemical
combination of two or more different elements. Compounds are
made up of small particles called molecules.
• The chemical and physical properties of a compound are
entirely different from those of the constituent elements. For
example, hydrogen is a combustible gas, while oxygen is a
supporter of combustion. But if they combine to form water, it is
neither combustible nor a supporter of combustion
• Compounds are the chemical combination of two or more
elements. Chemical combination usually takes place if you
applied heat or electricity to the combination. There are some
compounds that can be formed by simply adding water to the
substances that you are going to combine.
Common examples of compounds include water, the table salt,
sugar, muriatic acid, bleach, baking soda and alcohol

5. Mixtures
They are materials which are made up of two or more different
substances which are mixed but are not combined chemically.
Mixtures are usually created if the substances being combined are
simply mixed in a container. You did not apply heat nor electricity
to the mixture.
• Mixtures are usually created if the substances being combined
are simply mixed in a container. You did not apply heat nor
electricity to the mixture.
• Mixtures can be classified further into two – homogeneous
mixtures and heterogeneous mixtures.

6. • Homogeneous mixtures are mixtures wherein the
composition and appearance of the mixture is the same
throughout the solution.
• Homogeneous mixtures contain only one phase
• Basically, if we say homogeneous mixture, most of the
time, you will not be able to distinguish the different
components of the mixture.
• For example, if you mix sugar and water, the result is a
homogeneous mixture. While it is true that it is a
combination of solid (the sugar) and liquid (the water).
Once they are mixed, you will no longer distinguish where
the sugar is. You will only see one phase – liquid.

7. • Heterogeneous mixtures are made of different substances
that remain physically separate even if you mix them. They
have always more than one phase.
• Examples of mixtures include sand mixed with sugar, a
bowl of cereal, and a mixture of oil and water.
• When you look at a heterogeneous mixture, you can easily
distinguish some of the components that make up the
mixture.
• Immiscible liquids – liquids that will never mix such as oil
and water, will always form a heterogeneous mixture. No
matter how hard you will mix them, oil and water will
eventually separate. You can now see where the water is
and where the oil is.

8. • Mixtures can also be classified as solutions, suspensions or
colloids.
• Solutions are mixtures in which the particles are
completely dissolved in the solvent.
Since the solute is completely dissolved, the mixture is
homogeneous – it only has one phase. Since the solute is
completely dissolved, you cannot separate the solute and
solvent just by using a filter paper. In solutions, light can pass
through them.
• In a solution, the particles being dissolved are known
as solute. The particles that dissolve are known as solvent.
• In a solution, the solute is very small that you won’t be able
to see it with a naked eye.

9. • In suspensions, the particles are big that they will settle
down the bottom of the container when the suspension is
left undisturbed.
They are heterogeneous mixtures. This means that the
components of the particles really do not mix.
The solute of a suspension is larger than colloids and
solutions. These particles can be seen with the naked eye
An example of a suspension is soil mixed in water.
Particles of a suspension exhibit sedimentation.
Sedimentation is tendency of particles to settle out of the
suspension under the effect of gravity.

10. • In colloids, the particles are bigger than molecules. However,
they are still small, and are still, cannot be seen by the naked
eye.
Colloidal particles are electrically charged. In addition, they move
in random and zigzag motion. This random movement is known
as Brownian movement.
Also, the particles have a light scattering effect called the Tyndall
Effect. Because of this, if you illuminate a colloid, you can see the
particles. An example of colloid is dust in air. Normally, you cannot
see the dust suspended in air. However, if let us say, they pass
through the sunlight coming inside your room, then, you can now
see them.
In a colloid, dispersion medium is the medium in which the
substances in form of colloidal particles are dispersed.

11. • Dispersed phase is the substance distributed in the dispersion
medium. They are also known as the colloidal particles. In the
picture above, the solid dust particles are the dispersed phase
and the air is the dispersion medium
• There are many types of colloids. The name of the colloid
depends on what the dispersed phase and dispersion medium
is.

12. Common
Compounds around
Us
Matter and its Properties

14. Separation
Techniques
Matter and its Properties

15. • Paper chromatography is a mixture separation method
wherein the mixture to be separated is smeared on a
filter paper. The paper is then placed in a solvent and
as the paper gets soaked upwards, the solvent attracts
the various chemicals in the mixture. Different
chemicals have different rates of attractions to the
solvent. Because of this, chemicals are being separated
because different chemicals travel at different speeds.
Chromatography is used to separate mixtures of colored
compounds. For example, if you want to separate the
components of a dye, you can use chromatography. It
cannot be used to separate an insoluble solid and a
liquid.

16. • Filtration is a mixture separation method wherein a
filter paper is used. It can be used to separate an
insoluble solid and a liquid. It cannot be used to
separate mixtures with solutes completely dissolved in
water. The filter paper is placed in a funnel. The funnel
is then placed on top of a container. The mixture to be
separated is then poured in the funnel. The liquid part
then separates from the solid part and it drains
through the filter paper into the container.
In filtration, the solid particles found on the filter paper
are known as the residue. The liquid extracted from the
process is called the filtrate.

17. • Evaporation is a mixture separation method wherein the
mixture is heated. It can be used to separate components
of a mixture wherein the solid solute will be the only thing
recovered. The solvent will be evaporated away. No solvent
left, leaving the solute behind.

18. • Distillation is a mixture separation method wherein the mixture is heated
until it boils. It can be used to separate components of a mixture wherein
the solid solute and the liquid solvent can both be obtained. As the
solution boils, the solvent becomes vapor and it passes through the
condenser. As the solvent evaporates, the solute will be left behind inside
the first container. As for the vapor, it changes from gas to liquid as it
passes through the condenser. The solvent will now be extracted on the
second container.
In distillation, the solid particles left on the first container are known as
the residue. The liquid extracted on the second container as a result of
condensation is known as the distillate.

19. • Fractional distillation is a variation of distillation. It is used to separate a
liquid mixture formed by liquids of differing boiling points. It can be used
to separate miscible and immiscible liquids. For example, you can use
fractional distillation to separate oil and water and also to separate
alcohol and water.
• Decantation is a mixture separation method wherein a mixture of solid
and liquid or two immiscible liquids are allowed to settle and separate by
gravity. Once the mixture components have separated, the lighter liquid
is poured off leaving the heavier liquid or solid behind.