Download - Chapter 1 STATES OF MATTER REVISION PPT
Chapter 1
STATES OF MATTER
REVISION PPT
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1.1 States of Matter
TB Pg 3-6
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+WHAT IS MATTER?
Matter is something that occupies space
and has mass.
+MATTER
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Whichever chemical substance we study, we
find that the substance can exist in three
different forms (physical states) depending
on the conditions.
States of Matter
THE THREE STATES OF MATTER
SOLID
LIQUID
GAS
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+States of matter
Solid Liquid Gas
Has a fixed shape No fixed shape
Takes the shape of the
container
No fixed shape
Has fixed volume Has fixed volume No fixed volume
Takes the volume of the
container
Incompressible Can be compressed a bit Easily compressible
Does not flow Generally flows easily Flows easily
High Density Moderate to high density Low density
+Changes in State
Melting/Freezing
Boiling(vaporization)/Condensing
Sublimation
Evaporation
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+Conversion from one state to another
+Melting and Freezing Point
The temperature at which a substance turns to a liquid is
called the melting point.
The temperature at which a liquid gets converted back to a
solid is called freezing point.
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+Evaporation
If a liquid is left with its surface exposed to air, it evaporates.
When liquid changes into gas in this way, the process is
called evaporation.
It occurs from the surface of the liquid.
The larger the surface are, the faster the liquid evaporates.
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+Boiling
At a certain temperature a liquid becomes hot enough for
gas to form within the liquid and not just at the surface.
This process is known as boiling.
The temperature at which a liquid changes to gas is called its
boiling point.
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+Volatile and Volatility.
Volatile substance are those substances which evaporates
easily.
It’s a liquid with a low boiling point.
Volatility is the property of how easily a liquid evaporates.
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+
1.1 STATES OF MATTER
TB Pg 7-10
+PURE SUBSTANCE
A pure substance consists of
only one substance without
any contaminating impurities.
A pure substance melts and
boils at definite temperatures.
+
CRITERIA FOR PURITY
The purity of a substance can be measured by :-
1. Its melting point:- Pure substances have a sharp melting point.
If impurities are present then melting occurs over a wide range
of temperature.
2. Its boiling point:-Pure substances have a sharp boiling point. If
impurities are present then boiling occurs over a wide range of
temperature.
+STATE OF A SUBSTANCE
A substance’s melting and boiling points in relation
to the temperature (standard taken as 250C)
determine whether it is usually seen as a solid,
liquid or gas.
For example, if the melting point is below 250C and
the boiling point is above 250C, the substance will
be a liquid at room temperature.
+EFFECT OF IMPURITIES
Impurities often affect the value of melting and
boiling point of a substance.
An impure substance sometimes melts or boils over
a range of temperatures, not at the precise point of
the pure substance.
When impurities are present the freezing point
decreases and the melting point increases.
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120
90
60
30
0
2 4 6 8 100
Te
mp
era
ture
(°
C)
Time (s)
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Heating and cooling curves
Boiling
Point
Melting
Point
+What happens on heating
Matter is made up on small particles which are in constant
motion.
When you heat matter, the particles of matter absorb the heat
energy and begin moving faster (in other words they gain
kinetic energy).
As more energy is provided the chemical bond between the
particles become weaker and hence there is change is the state
of matter.
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1.2 KINETIC THEORY OF MATTER
TB Pg 11-14
+1.2 Kinetic Theory of Matter
Kinetic Theory of matter
explains the relation between
matter and energy of the
particles present in matter.
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+ 22
Main points of Kinetic Theory of
Matter
1) All matter is made up of very small particles
called atoms. Different substances contain
different types of particles such as atoms,
molecules or ions.
+Main points of Kinetic Theory of
Matter2) These tiny particles are always in
motion.
Increase in temperature = increase motion of
particles
decrease in temperature = decrease in
motion of particles
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+Main points of Kinetic Theory of
Matter
3) The freedom of movement and
arrangement of particles is different for the
three states of matter.
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+Main points of Kinetic Theory of
Matter
4) The pressure of the gas is produced by the
atoms or molecules of the gas hitting the
walls of the container. The more often the
particles collide with the walls, the greater
the pressure.
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+STATES OF MATTER AND KINETIC
THEORY
+
1.3 MIXTURES OF SUBSTANCES AND DIFFUSION
TB Pg 14-18
+What is a mixture?
When two or more materials
or substances are mixed
together but do not chemically
combine.
This means they retain their
original properties.
This means they can be
separated by physical means.
+TYPES OF MIXTURES
HOMOGENEOUS
MIXTURESHETEROGENEOUS
MIXTURES
The prefixes "homo"-
indicate sameness
The prefixes: "hetero"-
indicate difference.
A homogeneous mixture has
the same uniform
appearance and
composition throughout.
A heterogeneous mixture
consists of visibly different
substances or phases.
+Solutions
When the states are completely mixed to become
one single state or phase the mixture is called a
solution.
+Solutions
The solid that dissolves in a liquid is called solute.
The liquid in which the solid dissolves is called the
solvent.
+SOLUTIONS
If a substance dissolves in a solvent it
is said to be soluble and if does not
dissolve it is said to be insoluble.
When two liquids mix with each other
they are said to be miscible and if
they don’t mix they are said to be
immiscible.
Alloys are mixtures of metals.
+Solubility of solids in Liquids
+
A concentrated solution contains a
high proportion of solute.
A dilute solution contains a small
proportion of solute.
A solution is called saturated when no
more solute can be dissolved in it.
Solubility of solids in Liquids
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The concentration of solute in a
saturated solution is the solubility of
the solute at that temperature.
The solubility of most solids increase
with temperature.
Solubility
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What is diffusion?
Diffusion is the random
movement of particles that
causes them to spread out and
mix with other particles.
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Diffusion
Diffusion is a process by which particles of matter move from a region of higher
concentration to a region of lower concentration.
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EXAMPLE
For example, the smell of
aftershave or perfume diffuses
and is detected by people on
the other side of a room.
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Factors affecting Diffusion
#1: Temperature
The higher the temperature,
the faster the particles move,
the faster the rate of diffusion
40Factors affecting Diffusion
#2: Mass of particles
The smaller the mass,
the faster the particles diffuse
41Rate of diffusion
cotton
wool
soaked in
ammonia
gases
meet
here
cotton wool
soaked in
hydrochloric
acid solution
In this experiment, two gases diffuse towards
each other in a sealed glass tube.
When the gases meet, they
react and form a ring of
ammonium chloride, which is
closer to one end of the tube
than the other. Which gas
particles diffuse faster?
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The ammonia particles have
travelled further down the tube
so they must have diffused at a
faster speed.