HMCS Max Bernays Pre-Deployment Brief (May 2024).pptx
is matter around us pure
1. CHAPTER - 2
IS MATTER AROUND US PURE
CLASS :- IX
SCHOOL :- DPS BANGALORE NORTH
2. 1) Classification of matter :-
On the basis of chemical composition matter is classified into two
main types. They are pure substances and mixtures.
Pure substances are of two types. The are elements and compounds.
Mixtures are of two types. They are homogeneous mixtures and
heterogeneous mixtures.
Matter
Pure substances Mixtures
Elements Compounds Homogeneous Heterogeneous
mixture mixture
3.
4. Pure Substance-
A pure substance is one which is made
up of only one kind of particle.
§ EX- PLATINUM
Pure substance are of two types-
1-Element
2-Compound
5. Types of pure substances :-
Pure substances are of two types. They are elements and
compounds.
i) Element :- is a basic form of matter which cannot be broken down
into simpler substances by chemical reactions. Elements are of
three types. They are metals, non metals and metalloids.
Properties of metals :-
They have lustre. They are malleable and ductile. They are good
conductors of heat and electricity. They are sonorous.
Eg :- iron, aluminium, zinc, mercury, copper, silver, gold etc.
Properties of non metals :-
They do not have lustre. They are not malleable or ductile. They are
poor conductors of heat and electricity. They are not sonorus.
Eg :- hydrogen, oxygen, nitrogen, iodine, carbon, sulphur,
phosphorus etc.
Properties of metalloids :-
Metalloids are elements which show some properties of metals and
some properties of non metals.
Eg :- boron, silicon, germanium etc.
6. Element are also of three types-
§ Metals-
§ Nonmetals-
§ Metalloids-
8. Mixture are of two types-
1-Homogeneous Mixture
2-Heterogeneous Mixture
A mixture is a substance which consists of two or more
elements or compounds not chemically combined together
MIXTURE
11. 5) Colloidal solution :-
A colloidal solution is a heterogeneous mixture of two
or more substances.
Eg :- mixture of starch in water, mixture of egg albumin
in water, milk, air containing dust and smoke etc.
12. Properties of colloidal solution
i) Colloidal solution is a heterogeneous mixture.
ii) The particle size range from 1- 100 nm
ii) The particles cannot be seen by the naked eye.
iii) The solute particles cannot be separated by filtration.
iv) The solute particles do not settle down and the solution is stable.
v) The particles scatter a beam of light passing through it and the
path of light is visible in the solution.
vi) The particles of a colloid collide with each other and move randomly
in the solution. This random zig-zag motion of the colloidal particles is
called Brownian movement.
13. Tyndall effect :-
When a beam of light is passed through a colloidal
solution, the colloid particles scatter the beam of light and
the path of light becomes visible in the solution. This effect
is called Tyndall effect.
Tyndall effect can be seen when light enters a room
through a small hole due to scattering of light by the dust
and smoke particles.
Tyndall effect can be seen in a dense forest due to
scattering of light by water droplets in the mist.
16. 6) Suspension :-
A suspension is a heterogeneous mixture of two or
more substances in which the solute particles do not
dissolve but remain suspended in the bulk of the medium.
17. Properties of suspension
• i) Suspension is a heterogeneous mixture.
• ii) The particles can be seen by the naked eye.
• iii) The solute particles can be separated by filtration.
• iv) The solute particles settle down and the solution
is unstable.
• v) The particles scatter a beam of light passing
through it and the path of light is visible in the
solution
18. SATURATED AND UNSATURATED SOLUTION
Saturated solution :- is a solution which cannot dissolve
any more of a solute at a given temperature.
Unsaturated solution :- is a solution which can dissolve
some more of the solute at a given temperature.
Preparation of a saturated solution :-
Take 50ml of water in two beakers. Add salt in one beaker
with continuous stirring till no more salt dissolves in it.
Similarly add sugar in the other beaker with continuous
stirring till no more sugar dissolves in it. We get saturated
solutions of salt and sugar.
• If the mixtures are heated it dissolves some more of
the solute.
• The solubility of different substances are different.
• The solubility of substances varies with temperature.
19.
20. Solubility :- of a substance is the amount of solute which
can be dissolved in 100 g of the solvent to form a saturated
solution at a given temperature.
Effect of temperature on
solubility
Effect of pressure on solubility
1.Solubility of solid in liquids-
solubility increases with
increase in temperature
1.Solubility of solid solute in
liquids-Pressure has no effect
2.Solubility of gas in liquids-
solubility decreases with
increase in temperature
2.Solubility of gas in liquids-
solubility increases with
increase in pressure.
21. Concentration of a solution :-
The concentration of a solution is the amount of solute present in a given
amount of the solvent or solution.
The concentration of a solution can be expressed as
Mass of solute X 100
• Mass by mass percentage of a solution = Mass of solution
• Mass by volume percentage of a solution = Mass of solute X 100
Volume of solution
• Volume by volume percentage of a solution = Volume of solute x100
Volume of solution
•
22. Concentration of a solution
Answer the following questions
Q1. A solution has been prepared by dissolving 5 g of urea in 95 g
of water. What is the concentration of solution ?
Q2. A solution of 5 ml of alcohol mixed with 75 ml of water. Calculate
the concentration of the solution in terms of volume percent.
Q3. During an experiment, two students were asked to prepare a
10%(mass/mass) solution of salt in water. Rahul dissolved 10 g of salt in
100 g of water while Priya prepared it by dissolving 10 g of salt in water
to make 100 g of solution.
a) Do the two solutions have same concentrations ?
b) Calculate mass/mass percentage in each case.
c) Whose measurements are correct for the experiment ?
23. Concentration of a solution
Answers
Q1.
Mass percentage (Mass %) =Mass of solute/Mass of solution x100
solute=urea
Mass of solute =5g
solvent= water
Mass of solvent =95 g
solute+ solvent =solution
mass of solute +mass of solvent =mass of solution
95+5 =100 g
Mass percentage ( mass%) = 5/100 X100
=5%
24. Q2 : Concentration of solution =
volume of solute/volume of solution x 100
volume of solute = volume of alcohol =5 ml
volume of solution = volume of water =75 ml
volume of solution = (5+75) =80 ml
concentration of solution =5/80 x100 =6.25%
25. Q3.a) No, the two solutions do not have the same concentration.
b) In the solution prepared by Rahul,
Mass of salt=10 g
Mass of solution (100+10) g
Mass percentage of salt = 10/110 x 100 =9.09 %
In the solution prepared by Priya,
Mass of salt =10 g
Mass of solution =100 g
Mass percentage of salt = 10/100 x100 =10%
c) The measurements made by Priya are correct
26. Separating the components of a mixture :-
The components of a heterogeneous mixture can be
separated by simple methods like hand picking, sieving,
filtration etc.
Sometimes special techniques are used to separate the
components of mixtures like :-
i) Evaporation
ii) Centrifugation
iii) Decantation (Using separating funnel)
iv) Sublimation
v) Chromatography
vi) Simple distillation and fractional distillation
27. i) Evaporation :-
This method is used for separating a volatile component
(solvent) from a non volatile component (solute) by heating
the mixture.
Eg :- Ink is a mixture of a dye and water. If some ink is
heated in a dish, the water evaporates and the dye is left in
the dish. Similarly we can separate a mixture of salt and
water or sugar and water by evaporation.
dish
Mixture of salt and water
stand
burner
wire gauze
28. ii) Centrifugation :-
The method of separating denser particles and lighter
particles from a mixture by using a centrifuging machine
is called centrifugation.
Eg :- If we take some milk in a centrifuging machine and
spin it rapidly, the cream separates from the milk because
cream is less dense than milk.
29. iii) Decantation using separating funnel :-
This method is used for separating a mixture of
immiscible liquids. Liquids separate into different layers
depending on their densities.
Eg :- If we take a mixture of kerosene oil and water in a
separating funnel, it forms separate layers of oil and
water. The water can be separated by opening the stop
cock. After the water flows out the stop clock can be
closed.
water
kerosene
water
30. iv) Sublimation :-
This method is used to separate a mixture of a
sublimable component from a non sublimable component
by heating the mixture.
Eg :- If a mixture of ammonium chloride and common
salt is heated, the ammonium chloride sublimes and can
be cooled and solidified and collected and salt is left
behind.
Mixture of
Ammonium chloride
and salt
Ammonium chloride
vapours
Ammonium chloride
solidified
Inverted funnel
Cotton
China dish
Burner
31. Purification of solids by crystallisation :-
Crystallisation is the process of obtaining a pure solid in the form of
crystals from its solution.
Eg :- By crystallisation we can obtain pure copper sulphate from its
solution.
Dissolve about 5g of CuSO4 in minimum amount of water. Stir with the
help of a glass rod for about five minutes so that CuSO4 completely
dissolves in water. Filter the solution to remove the impurities.
Evaporate the solution in a china dish to get a saturated solution. Cover
the solution with a filter paper and allow it to cool. Pure CuSO4 crystals
are formed.
Impure copper sulphate Pure copper sulphate crystals
32. v) Chromatography :-(Kroma means colour)
This method was used for the separation of colours, so this name was
given.
Chromatography is the technique used for the separation of different
solutes dissolved in the same solvent.
Eg :- Put a drop of ink near one end of a strip of filter paper and dip the
end of the paper in a test tube containing water. Ink is a mixture of two
or more coloured components. The component which is more soluble in
water rises faster and get separated.
33. vi) Distillation :-
This method is used for separating a mixture of miscible liquids by
boiling the mixture and cooling and condensing the vapours.
Simple distillation :- is used for separating a mixture of two
miscible liquids having sufficient difference in their boiling points.
Eg :- If a mixture of acetone and water is heated in a distillation
apparatus, the acetone which has a lower boiling point than water first
boils and cools and condenses and is separated from the water.
Mixture of acetone
and water
Acetone
34. FRACTIONAL DISTILLATION
Fractional distillation is used for separating a mixture of two or more
miscible liquids whose difference in boiling points is less than 25K.
The apparatus used for fractional distillation is similar to that used for
simple distillation except that a fractionating column is fitted between
the distillation flask and condenser. The fractionating column has glass
beads which increases the surface for the vapours to cool and
condense. Fractional distillation is used for separating the components
of petroleum, separating the different gases from air etc.
35. Separation of components of air :-
Air is a mixture of gases. The components of air can be separated by
fractional distillation.
Air is compressed by increasing the pressure and cooled by
decreasing the temperature to get liquid air. The liquid air is then
allowed to warm up slowly in a fractional distillation column. Then the
different components separate at different heights depending on their
different boiling points.
Compress and cool by increasing
pressure and decreasing temperature
Allow to warm up slowly
In fractional distillation column
Gases get separated at different heights
Boiling points (OC) Oxygen – 183, Argon – 186 , Nitrogen – 196
Air
Liquid air
36. Differences between mixtures and compounds :-
Sl.No. Mixture Compound
1 It is composed of two or more
elements or compounds
mixed together.
It is composed of two or
more elements chemically
combined together.
2 The composition of the
components is in any ratio.
The composition of the
components is in a fixed
ratio.
3 It shows the properties of the
components.
It shows different properties
than the components.
4 The components can be
separated by physical
methods.
The components can be
separated only by chemical
methods.
37. d
Criteria Iron filings and Sulphur mixture Iron Sulphide compound
1.Preparation Iron filings and Sulphur is a
mixture.(heterogeneous) ( mix
sulphur powder and iron filings in a
china dish)
Iron Sulphide is a
compound(homogeneous)
(when you heat iron filings
and sulphur in a china dish ,a
black mass will be formed
2.Adding Carbon
disulphide solution (CS2
SOLUTION))
Sulphur dissolves when you add CS2
solution in this mixture
Nothing will happen when you
add CS2 solution in this
compound
3.Effect of magnet Bring a magnet near the mixture. Iron
filings will readily cling to the
magnet.
Nothing will happen when you
bring magnet near the
compound.
3.Adding dil.HCl
solution
Fe+ 2HCl(aq àFeCl2(aq) +H2(g),
Hydrogen gas is released
(odourless)
FeS(s)+ 2HCl(aq)---->
FeCl2(aq)+ H2S(g), Hydrogen
Sulphide gas is released.
(smells like rotten eggs)
Differentiate between Iron filings and sulphur mixture and Iron sulphide
compound
38.
39. CHEMICAL CHANGE
• It is a change in which a new substance is made.In
this change the chemical properties of the substance is
change. These changes are irreversible.
40. PHYSICAL CHANGE
• The change in which only transformation of
state is happen, no new substance is made
are called physical change. These changes
are reversible.
41. ANNEXURE
• https://www.youtube.com/watch?v=vrbuAO4t1_w –types of
pure substsance
• https://www.youtube.com/watch?v=X7b8_9wAREE-Alloy
• https://www.youtube.com/watch?v=DLZ6XSc2Dws -
Homogeneous mixture and heterogeneous mixture
• https://www.youtube.com/watch?v=uIYCyIaU8OI –true
solution,suspension,colloid
• https://www.youtube.com/watch?v=8Xcpq6e8pBY –Tyndall effect
• https://www.youtube.com/watch?v=yqI5R6KVVUE -concentration of
solution
• https://www.youtube.com/watch?v=1c1XzqtAJrk separation
techniques
• https://www.youtube.com/watch?v=C2RqAE0wbqk –differentiate Iron
Sulphide and Iron and Sulphur mixture
• https://www.youtube.com/watch?v=IwFkM6Jn2O4 – physical and
chemical change
