it is a chapter of science and it is a subject of chemistry

1. 1)What is mixture?
2)What is solution?
3)What is suspension?
4)Separating the components of a
mixture.
5)Physical and Chemical changes.

3.  Mixture are constituted by more than one kind of
pure form of matter , known as a substance.
 A substance cannot be separated into other kinds
of matter by any physical process.
 For example:- Sugar is a substance because it
contains only one kind of pure matter and its
composition is the same throughout .
 Therefore, we can say that a mixture contains more
than one substance.

5.  Types of mixtures:-
 Depending upon the nature of the components that
form a mixture, we can have different types of
mixtures.
 WHAT IS SOLUTION ?
 A solution is a homogeneous mixture of
two or more substances . we come across
various types of solutions in our daily
life like lemonade , soda water etc… are
the examples of solutions.

6.  Solution as a liquid that contains either a
solid, liquid or a gas dissolved in it. But, we
can also have solid solutions and gaseous
solutions.
 In a solution there is homogeneity at the
particle level. A solution has a solvent and a
solute as its components.
 The solution that dissolves the other
component in it is called as solvent.
 Solution that is dissolved in the solvent is
called as solute.

7.  Concentration of a solution:-
 The amount of solute present in a solution, it
can be called a dilute , concentrated or a
saturated solution. Dilute and concentrated
are comparative terms.
 When no more solute can be dissolved in a
solution at a given temperature , it is called a
saturated solution.
 The amount of the solute present in the
saturated solution at temperature is called its
solubility.
 If the amount of solute contained in a solution
is less than the saturation level , it is called an
unsaturated solution.

8.  The concentration off a solution is the amount
of solute present in a given amount of
solution, or the amount of solute dissolved in
given mass or volume solvent.
 Concentration of solution = amount of solute
 amount of solution
 There are various ways of expressing the
concentration of a solution, but here we will
learn only two methods.
 1stmethod=(mass of solute/mass of solution)
100 (mass percentage of a solution)

9.  2nd method= mass of solute
 volume of solution multiplied
with 100.
What is suspension?
 Non –homogeneous systems like solids are
dispersed in liquids, are called suspension.
 A suspension is a homogeneous mixture in
which the solute particles do not dissolve but
remain suspended throughout the bulk of the
medium.
 Particles of a suspension are visible to the
naked eye.

10.  What is a colloidal solution?
 The solute particles settle down when a
suspension is left undisturbed, that is, a
suspension unstable is called as colloidal
solution.
 The particles of colloidal are uniformly spread
throughout the solution.
 Due to the relatively smaller size of particles,
as compared to that of a suspension, the
mixture appears to be homogeneous.
 But actually a colloidal solution is a
homogeneous mixture.

11.  Because of small size, we cannot see them with a
naked eye. But these particles easily scatter a beam of
visible light. These scattering of a beam of light is
called the Tyndall effect.
 Through effect can also be observed when a fine
beam of light enters a room through a small hole.
This happens due to the scattering of light by the
particles of dust and smoke in the air.
 Tyndall effect can be observed when sunlight passes
through the canopy of a dense forest.
 The components of colloidal solution are the
dispersion medium. The component in which the
dispersed phase is suspended is known as the
dispersing medium.

12.  Tyndall effect of razor light and in forest
sunlight.

13.  Colloids are classified according to the state ( solid,
liquid, gas) of the dispersed phase.
 separating the components of a
mixture:-
 Most of the natural substances are not
chemically pure.
 Methods of separation are used to get
individual components of a mixture.
 Separation makes it possible to study and use
the individual components of a mixture.
Heterogeneous mixtures can be separated into
their respective constituents by simple
physical methods like handpicking, sieving ,
filtration that we use in our daily life.

14.  Sometimes special techniques have to be used for the
separation of the components of a mixture.
 How can we separate cream from
milk?:-
 Some times the solid particles in a liquid are
very small and pass through a filter paper. For
such particles the filtration technique cannot
be used for separation. Such mixtures are
separated by centrifugation. The principle is
that the denser particles are forced to the
bottom and the lighter particles stay at the top
when spun rapidly.

16.  The principle is that immiscible liquids separate
out in layers depending on their densities.
 How can we separate a mixture of salt
and ammonium chloride?:-
 Ammonium chloride changes directly solid to
gaseous state on heating.
 So, to separate such mixtures that contain a
sublimation volatile component from a non-
sublimation impurity, the sublimation process is
used.
 Some example of solids which sublime are
ammonium are ammonium chloride, camphor,
naphthalene and anthracene.

17. sublimation

18.  Is the dye in black ink a single colour
?:-
 The ink that we use has water as the solvent
and the dye is soluble in it. The water rises on
the filter paper it takes along with it the dye
particles.
 A dye is a mixture of two or more colours. The
coloured component that is more soluble in
water, rises faster and in this way the colours
get separated.
 This process of separation of components of a
mixture is known as chromatography.

19.  How can we separate a mixture of
two miscible liquids?:-
 Distillation is the process of separating the
component substances from a liquid mixture
by selective evaporation and condensation.
 It is used to separate of components of a
mixture containing two miscible liquids that
boil without decomposition and have
sufficient difference in their boiling points.
 To separate a mixture two or more miscible
liquids for which the difference in less than
25k , fractional distillation process is used.

21.  The apparatus is similar to that for simple
distillation, except that a fractionating column
is fitted in between the distillation flask and
the condenser.
 How can we obtain different gases
from air?:-
 Air is homogeneous mixture and can be
separated into its components by fractional
distillation.
 The flow diagram shows the steps of the
process.

23.  Flow diagram
shows the process
of obtaining gases
from air:-(Fig2.1)

24.  If we want oxygen gas from air (Figure2.2), we
have to separate out all the other gases present
in air.
 The air is compressed by increasing the
pressure and then cooled by decreasing
temperature to get liquid air.
 The liquid air is allowed to warm-up slowly in
a fractional distillation column, where gases
get separated at different heights depending
upon their boiling points.

26.  How can we obtain pure copper
sulphate from an impure sample?:-
 The crystallization method is used to purify
solids. For example, the salt we get from sea
water can have many impurities in it. To
remove these impurities, the process of
crystallization is used.
 Crystallization is a process that separates a
pure solid in the form of its crystals from a
solution.
 Crystallization technique is better than simple
evaporation technique as:-

27.  (1) Some solids decompose or some, like sugar, may
get charred on heating to dryness.
 (2) Some impurities may remain dissolved in the
solution in even after filtration. On evaporation these
contaminate the solid.
 Physical and chemical changes:-
 The properties that can be observed and
specified like colour, hardness, rigidity,
fluidity, density, melting point, boiling point
etc… are the physical properties.
 The interconversion of states is a physical
state because these changes occur without a
change in composition.

30.  On the basis of their chemical
composition, substance can be classified
either as elements or compounds.
 Elements:- Elements can be normally
divided into metals, non-metals and
metalloids.
 Metals usually some or all of the
following particles:-

31.  They have a lustre.
 They have silvery-grey or golden yellow
colour.
 They conduct heat and electricity.
 They are ductile.
 They are malleable.
 They are sonorous.
 Non-metals usually show some or all of the
following properties:-
 They display a variety of colours.
 They are poor conductors of heat and
electricity.

32.  They are not lustrous, sonorous or malleable.
 Table of mixtures and compounds:-

33.  1) Name three materials that are used as filters?
 Ans:-Cotton, filter paper, sand.
 2) Name the method to separate iron from waste
material?
 Ans:-Magnetic separation.
 3) What method will you use to separate copper sulphate
from its solution?
 Ans:-Crystallization.
 4) Is the rusting of iron in air a physical change or
chemical change?
 Ans:-Chemical change.

34.  5) Name the substance that cannot be decomposed
under ordinary circumstances either by a physical or
chemical change?
 Ans:-Element.
 6) Name the substance that is composed of atoms of
different elements in a fixed proportion?
 Ans:-Compound
 7) Name the material which shows average
properties of the constituents contained it?
 Ans:-Mixture.
 8) At a given temperature, the solubility of a
compound is 2%. 500g of a solution contains 10g of
this compound. State whether the solution is
saturated or unsaturated?
 Ans:-Saturated solution.

35.  9) The path of light gets scattered when passed
through milk. What is this effect?
 Ans:-Tyndall effect.
 10) Name the process to separate particles of
colloidal solution?
 Ans:-Centrifugation.
 11) What happens when dilute h2so4 is added to iron
sulphide?
 Ans:-h2s gas is evolved.
 12) What process is used to separate husk from corn?
 Ans:-winnowing.
 13) how is ammonium chloride separated from
sodium chloride?
 Ans:-sublimation.

36.  14) Which method is mostly used for purification of
solids>
 Ans:-crystallization.
 15) Name the process used for separation of gases
from liquid air?
 Ans:-Distillation.
 16) Is blue ink a compound or a mixture?
 Ans:-Mixture.
 17)What is the process called in which pigments of
natural colours can be separated?
 Ans:-chromatography.
 18) Which technique is used in dairies and home to
separate butter from cream?
 Ans:-Centrifugation.

37.  1) Which one of the following is a physical
change?
 (A)Burning of magnesium.
 (b)Exposure of iron to air and moisture.
 (c)Dissolution of sugar in water.
 (d)Formation of a compound.
 2) Which one of the following may be termed
as pure substance?
 (a)sodium chloride (b)soft drink
 (c)aerosol (d)soil

38.  3) Select a compound out of the following:
 (a) air
 (b) solution
 (c) marble
 (d) stainless steel
 4) Select a heterogeneous mixture out of the following:
 (a) air
 (b) solution
 (c) emulsion
 (d) alloy
 5) Tyndall effect can be shown by a:
 (a) solution (b) true solution
 (c) mixture (d) colloidal solution

39.  6) Select a colloidal solution out of the following:
 (a) gold ornaments
 (b) sand grains
 (c) lime water
 (d) paint
 7) Identify solution among the following mixtures:
 (a) gun powder
 (b) soil
 (c) blood
 (d) Aerated water
 8) Solution of soap water is a
 (a) true solution (b) colloidal solution
 (c) suspension (d) none of these

40.  9) A mixture of ammonium chloride and sand
can be separated by
 (a) decantation
 (b) centrifugation
 (c) sublimation
 (d) evaporation
 10) A solid from its solution cannot be
separated by:
 (a) sublimation
 (b) evaporation
 (c) crystallization
 (d) distillation

41. Made by :-
 Madhan
 S.k.karthick
 K.vihnesh
 K.dhamendar