Matter In Our Surrounding
Matter
Anything that occupies space, has mass and produce resistance is called
matter.
Volume
The space occupied by the matter is known as volume.
Substance
A substance is a kind of matter that cannot be separated into other kind of
matter by any physical process.
Physical nature of matter
• Matter is made up of the particles.
• Everything around us is made up of many tiny particles.
• Particles which made up the matter are constantly.
• Particles which made up the matter are atoms or molecules.
General characteristics of matter
• The matter has mass
• The matter occupies space
• The matter has inertia
• The matter affected by the gravity
• The matter cannot be destroyed
Physical nature of matter
• The prosperity is of matter can be categorised as physical or
chemical.
Physical properties
Physical properties can be measured without changing the identity is and the
composition of the substance.
Example :- colour, order, density, melting point, boiling point etc.
Chemical properties
Chemical property is described the weigh a substance may change on react
to form other substance.
Particle nature of the matter
The matter is composed of very small particles which cannot be further
subdivided.
Evidence for particles in matter
Most of evidence for the existence of particle in matter and their motion
comes from the experiment on diffusion or Brownian motion.
Characteristics of particles of matter
• The particles of matter are very very small.
• The particles of matter have spaces between them.
• Particles of matter are constantly moving.
• This properties can be explained by the brownion motion and diffusion.
Diffusion
Intermixing of particles of two different types of matter on their own is
called diffusion.
• Particles of matter attract each other.
Cohesive force
The force of attraction between the particles of some substance is known as
cohesive force.
Adhesive force
The force of attraction between the particles of different substances called
adhesive force.
Classification of matter
Matter can be classified into different categories depending upon their
physical or chemical nature.
1.) Based on state (physical classification)
2.) Based on purity or compression (chemical classification)
• Upto 1995, scientist have identified five state of matter.
• These main state of matter are solid, liquid, gas, plasma and Bose Einstein
condensate.
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Solid
• Due to the strong intermolecular attractive force between the constituent
particles, solids are rigid and possess a definite shape and definite
volume.
• Solids have definite melting point, high density and low compressibility.
• The molecules, atoms or ions that make up a solid are closely packed that
means they are held together by a strong forces and cannot move about.
Solids are classified into two groups based on arrangement of constituent
particles.
1. Crystalline solid
2. Amorphous solid
Crystalline solid
• Crystalline solid is the one in which the constituent particles are arranged
in a regular manner throughout the entire three dimensional network.
• A crystalline solid consists of a large number of repeating unit called unit
cell.
Crystal
A solid figure having planar surface, Sharp edge and a definite geometrical
shape.
Amorphous solid
Those solids in which the constituent particles are arranged in irregular
fashion.
• This resembles liquids, as they flow very slow at room temperature so it is
called super cooled liquid.
Example :- plastic, glass, rubber etc.
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Liquids
Liquids have definite volume but do not have definite shape.
Properties of liquids
1. Shape and volume
Shape :- molecular force between the liquid molecule are not so
strong to keep molecules in a fixed position therefore liquid do not have a
definite geometrical shape.
Volume :- due to appropriate attractive force they have definite
volume in comparison to gas.
2. Density
In comparison to guess in liquids the molecules are more closed to each
other therefor density of liquid is higher than that of gaseous state.
3. Diffusion
When to soluble liquids are placed close to each other then molecules of one
liquid enter in between the molecules of the other and the two liquid mixed
with each other.
• It is comparatively slow process because the velocity of liquid molecule
is very less in comparison to gas molecule.
4. Compressibility
Due to very large vacant space between the molecules, the property of
compressibility of gases is very high but the vacant space in between the
molecules in liquid is very less so compressibility of liquid is very less
as compared to gas.
5. Evaporation
• Evaporation is that process in which liquid changes into vapour state at
room temperature.
• The kinetic energy of molecule of liquid opposes the intermolecular force
of attraction which keeps them close therefore some molecule evaporate from
the surface and go to the vapour state.
Vapour pressure :- the pressure exerted by the vapour in equilibrium
state or condition with its a liquid at a given temperature is called vapour
pressure of that particular liquid.
6. Surface tension
The liquid surface is under tension due to unbalanced forces this is called
surface tension.
• It is an important property of liquid which directly proportional to the
intermolecular force between the molecules.
• A molecule in the bulk of the liquid is attracted equally on all sides so
that net attractive pull on the molecule is zero.
• A molecule which lies at the surface is subjected only to the attractive
forces of the molecule below it. this is because there is no molecule over
it, therefore surface molecules experiences a resultant downward attractive
force with in the liquid.
Effect of room temperature on surface tension
• Surface tension decreases with rise in temperature
• The decrease of surface tension with increase of temperature because of
the fact that the kinetic energy of the molecules increases as a result the
intermolecular force decreases and therefore surface tension also decreases.
Importance of surface tension
1. Capillary action
The rise of liquid in capillary is called capillary action.
• The rise of liquid in a capillary is due to the inward pull of surface
tension acting on the surface which pushes the liquid into the capillary
tube.
2. Spherical shape of drop
• The liquid drop have nearly a spherical shape because the surface tension
tries to decrease the surface area of the liquid to minimum surface
area for the given volume of liquid.
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Gas
• Gas is the third state of matter.
• Gas has no definite shape or volume.
• Due to very weak intermolecular force in gas is its molecules are in
greater motion and shows irregular movement therefore gases do not possess
definite size, shape and volume.
• Gases have very low density and high compressibility.
General characteristics of gases
1. Compressibility
The compressibility of gases is more than that of solids or liquids because
gases have large intermolecular space.
2.Exertion of pressure
• Solid exert pressure only in downward direction
• Liquid exert pressure downward as well as to the sides
• But gases exert pressure in all direction
3. Homogeneous nature
Gases have similar composition in all parts and are therefore homogeneous in
nature.
4. Liquification
Gases can be liquefied by cooling and by applying pressure.
5. Diffusion
All gases possess this property of intermixing with one another without any
mechanical add, to form a homogeneous mixture called diffusion.
Gas law
• By changing the temperature or pressure of any gas its volume also
changes.
Boyle's law
At constant temperature, the volume of a sample of a gas varies inversely
proportional to the pressure.
PV = Constant
| Pressure | Volume | |
| P | V | PV |
| P1 | V1 | P1V1 |
| P2 | V2 | P2V2 |
| P3 | V3 | P3V3 |
| P4 | V4 |
P4V4 |
P1V1 = P2V2 = P3V3 = ............... PV = Constant
Charle's law
The volume of a given amount of a gas at constant pressure varies directly
proportional to its absolute temperature.
Gay lussac law
At constant volume, the pressure of a given amount of a gas is directly
proportional to its absolute temperature.
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Avogadro's law
1. For solid, liquid and gas
One mole of any substance contain avogadro's number(NA) of particles
(molecules/ atoms/ions).
NA = 6.023 ⨯ 1023
2. For gases
The sample of different gases which contain the same number of molecules
occupies the same volume at the same temperature and pressure.
Graham's law of diffusion
the rate of diffusion or effusion of a gas at constant temperature and
pressure is inversely proportional to square root of its molecular mass.
Dalton's law of partial pressure
The total pressure of a mixture of gases which do not react with each other,
filled in a vessel is equal to the sum of particle pressure of the mixed
gases.
P = P1 + P2 + P3 + P4 ........
Combined gas law
Step 1 :-
Let us change the pressure of the gas from P1 to
P2 at constant temperature T1. The volume will
change from V1 to Vx
By applying Boyle's law
Step 2 :-
Let the temperature of the gas be now charged to T2 and
constant pressure P2. So that volume may change from Vx to V2
By applying Charle's law
Ideal gas equation
Those gasses which obey gas laws at all temperature or pressure or volume.
R = Proportionality constant
R = Universal gas constant
R = 0.821 l atm K-1 mol
R = 82.1 atm ml K-1 mol-1
R = 8.314 J mol-1 K-1
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Interconversion of matter
The phenomenon of change of matter from one state to another state and back
to original state by altering the condition of temperature or pressure is
called interconversion of matter.
The various state of matter can be interchanged into another by altering the
condition of
1. Temperature
2. Pressure
By altering the temperature of matter
(a) Interconversion of solid into liquid and vice versa.
The solid can be converted into liquid by heating them.
1. Melting or fusion
The process due to which a solid change into liquid state by absorbing heat
energy is called melting or fusion.
Melting point :- the constant temperature at which of solid changes into
liquid state at atmospheric pressure by absorbing heat is called melting
point.
2. Freezing or solidification
The process due to which a liquid change into solid state by giving out heat
energy is called freezing or solidification.
Freezing point :- the constant temperature at which liquid change into a
solid state by giving out heat energy is called freezing point.
Latent heat of fusion :- the amount of heat energy that is required to
change 1 kg of solid into liquid at atmospheric pressure at its melting
point is known as latent heat of fusion.
• Latent heat of fusion of ice is 3.34 x 10⁵ joule/kg.
Q. Why during melting of solid, temperature remain constant?
Ans.- Temperature do not increase during the melting of solid because heat energy is used up in breakdown the intermolecular forces between the particles.
(b) Interconversion of liquid into gases and vice versa.
1. Boiling or vaporization
The process due to which a liquid change into gaseous state by absorbing heat energy is called boiling.
Boiling point :- The constant temperature at which a liquid rapidly change into gaseous state by absorbing heat energy at atmospheric pressure is called boiling point.
2. Condensation or liquefaction
The process due to which a gas change into liquid state by giving out heat energy is called condensation.
Condensation point :- At constant temperature, gas change into liquid by giving out heat energy at atmospheric pressure.
Latent heat of vaporization :- The amount of heat, which is required to convert 1 kg of liquid to vapour or gas without any change in temperature is called latent heat of vaporization.
Q. why is steam causes more severe burns than boiling water at 100⁰c?
Ans.- As steam have absorb extra energy in form of latent heat of vaporization, steam at 100⁰c will be more dangerous than water at that temperature.
(c) Direct interconversion of solid into gaseous state and vice versa (sublimation)
Sublimation
Certain substances when heat pass directly from the solid state it changes to vapour state without being converted into liquid, this phenomenon is known as sublimation and the substance is known as sublimate.
Example :- camphor, iodine, naphthalene, ammonia chloride.
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By altering pressure
The difference in various state of matter is due to the difference in intermolecular space between their particles so when a gas is compressed the intermolecular space between its particles get decreased and ultimately it will be converted into liquid, so high pressure and low temperature can liquefy a gas.
Evaporation :- When liquid change into gases state below the boiling point is called evaporation.
Two conditions allow a molecule of a molecule in a liquid to escape The liquid state to the gaseous state.
1. It must at or near the surface.
2. It must have at least the minimum amount of the kinetic energy to overcome the intermolecular force.
Q. Why do we see water droplets on the outer surface of a glass containing ice cold water?
Ans.- The water vapour present in air are coming in contact with cold glass of water loses energy so water vapour gets converted to liquid state which we see in as water droplets.
Q. Why evaporation occurs?
Ans.- Molecules in the liquid state are constantly moving but at different speed. faster moving molecules at the surface of liquid break away from the attraction of other molecules and escape into the air. heating makes liquid evaporation faster because there are more fast moving molecules and therefore molecules can escape.
Q. Why should we wear cotton clothes in summer?
Ans.- Because cotton clothes absorb water much fastly and fast evaporation and evaporation causes cooling so we wear cotton clothes in summer.
Factors affecting evaporation
1. Temperature
2. Surface area
3. Humidity
4. Wind speed
5. Pressure
1. Temperature
With the increase in temperature the rate of evaporation increases.
Rate of evaporation ∝ Temperature
Reason :- On increasing temperature more number of particles get enough kinetic energy to go into the vapour state.
2. Surface area
Rate of evaporation ∝ surface area
• Evaporation is a surface phenomenon
• if the surface area is increased, the rate of evaporation increased.
3. Humidity
The amount of water vapour present in air is called humidity.
• When humidity of air is low, the rate of evaporation is high and water evaporates more rapidly.
• When humidity of air is high, the rate of evaporation is low and water evaporates very slowly.
4. Wind speed
Rate of evaporation is directly proportional to wind speed.
With the increase in wind speed the particles of water vapour move away with the wind.
5. Pressure
The rate of evaporation can also increase with the decrease in the gas pressure around a liquid.
• Cooling caused by evaporation.
Difference between boiling and evaporation
• Boiling takes place only at a particular temperature for a liquid whereas evaporation occur at all temperature.
• Boiling is a bulk phenomenon whereas evaporation is a surface phenomenon.
Plasma
Plasma is made of free electrons and ions of the element.
Example :- fluorescent light bulb are not like regular light bulbs, inside the tube is a gas.electricity flow through the tube when the light is turned on and charge up the gas this charging and exciting of the atom creates the glowing plasma inside the tube.
Example :- stars are big balls of gases at really high temperature, the high-temperature charge up the atoms and create plasma.
• Plasma are super hot or super excited atoms.
Bose Einstein condensate
• Condensation happens when several gas molecules come together due to loss of energy.
• Satyendra nath Bose and Albert Einstein had predicted it in 1920.
• In 1995 Cornell and weiman finally created this new state of matter.
• They are super and excited and supercooled atoms.
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