Notes of Is Matter Around Us Pure? | Class 12th Ncert
Introduction:
TOPIC IN THIS CHAPTER YOU WILL LEARN
☞Introduction
☞what are a mixture and its type
☞what is a solution and its characteristics
☞the concentration of a solution
☞what are a suspension and its characteristics
☞What are a colloidal solution and its characteristics
☞What are a colloidal solution and its characteristics
☞separation of the components of mixtures
☞separating a mixture of salt and ammonium chloride
☞Experiment to obtain coloured component(dye) from ink
☞separating a mixture of two miscible liquid
☞separating a mixture of salt and ammonium chloride
☞Experiment to obtain coloured component(dye) from ink
☞separating a mixture of two miscible liquid
☞obtaining different gases from the air
☞obtaining pure copper sulfate from an impure sample
☞Physical and chemical changes
☞Types of pure substances
☞Difference between mixtures and compounds
Introduction
☞Anything that occupies space and has mass is called matter.
☞Matter divided into two categories.
Matter
⬇
Categorized
______⬇_________
⬇ ⬇
Pure substances Mixtures
(Contain only one type of particles) (Contain two or more different kind of Particles)
Eg:- Eg:-
Salt,Gold,Oxygen e.t.c Air,Sand,sea water e.t.c
⬇ ⬇
____Categorized_____ __Categorized___
⬇ ⬇ ⬇ ⬇
Element Compound Homogeneous Heterogeneous
Eg:- Eg:- Eg:- Eg:-
Zinc(Zn),Iron(Fe) H2O Salt solution Oil in water
☞Mixture consists of more than one kind of pure substance which can be separated by physical method.
☞Homogeneous Mixture:-
Those mixtures in which the substances are completely mixed together and are indistinguishable from one another. Eg:- Sugar solution,Salt solution,Air,Alcohol and water mixture.
Sugar solution➡Sugar + Water
⬆
Makes compound
of mixture
☞All Homogeneous mixture are called solutions.
☞Heterogeneous Mixture:-
Those mixtures in which the substances remain separate and one another substances is spread throughout the other substance as small particles,droplets or bubbles.
Eg:- Sugar and sand mixture,Water and oil,Chalk Water.
A Heterogeneous mixture does not have a uniform composition throughout its mass and has visible boundaries of separation between the various constituents.
☞ Solute:- The substance 'which is dissolved' in liquid to make a solution is called 'solute'.Eg:- sugar
☞ Solvent:- The 'liquid' in which solute is dissolved is known as 'solvent'.
Eg:-Water
CHARACTERISTICS
☞Particles of a solution can not be seen even with a microscope.
☞Size of solute particles is less then 1nm(10-9m).
☞A solution does not scatter light.
☞It can not be separated by filtration.
☞Solute particles are very stable and do not settle down when left undisturbed.
CONCENTRATION OF A SOLUTION
☞A solution may have any amount of solute of solute in it.
☞The amount of solute present,in a given quantity of solution is known as concentration of a solution.
Mass of solute × 100
Concentration of solution= -------------------------
Mass of solution
Saturated and Unsaturated solution
☞Saturated solution:-A Solution in which,no more solute can be dissolved at the temperature is called saturated solution.
☞Unsaturated solution:-A solution in which more quantity of solute can be dissolved without raising its temperature is called unsaturated solution.
☞Solubility of a solids in liquids usually increases on increasing the temperature.
Salt,Gold,Oxygen e.t.c Air,Sand,sea water e.t.c
⬇ ⬇
____Categorized_____ __Categorized___
⬇ ⬇ ⬇ ⬇
Element Compound Homogeneous Heterogeneous
Eg:- Eg:- Eg:- Eg:-
Zinc(Zn),Iron(Fe) H2O Salt solution Oil in water
What is mixture and its type
☞Mixture consists of more than one kind of pure substance which can be separated by physical method.
Types of Mixture
☞(i)Homogeneous mixture
☞(ii)Heterogeneous mixture
Those mixtures in which the substances are completely mixed together and are indistinguishable from one another. Eg:- Sugar solution,Salt solution,Air,Alcohol and water mixture.
Sugar solution➡Sugar + Water
⬆
Makes compound
of mixture
☞All Homogeneous mixture are called solutions.
☞Heterogeneous Mixture:-
Those mixtures in which the substances remain separate and one another substances is spread throughout the other substance as small particles,droplets or bubbles.
Eg:- Sugar and sand mixture,Water and oil,Chalk Water.
A Heterogeneous mixture does not have a uniform composition throughout its mass and has visible boundaries of separation between the various constituents.
what is solution and its characteristics
SOLUTIONS
☞ A homogeneous mixture of two or more substances.
Eg:- sugar solution.soda water,e.t.c
Solution has two components:-
☞Solute
☞Solvent
☞ Solvent:- The 'liquid' in which solute is dissolved is known as 'solvent'.
Eg:-Water
CHARACTERISTICS
☞Particles of a solution can not be seen even with a microscope.
☞Size of solute particles is less then 1nm(10-9m).
☞A solution does not scatter light.
☞It can not be separated by filtration.
☞Solute particles are very stable and do not settle down when left undisturbed.
CONCENTRATION OF A SOLUTION
☞A solution may have any amount of solute of solute in it.
☞The amount of solute present,in a given quantity of solution is known as concentration of a solution.
Mass of solute × 100
Concentration of solution= -------------------------
Mass of solution
Saturated and Unsaturated solution
☞Saturated solution:-A Solution in which,no more solute can be dissolved at the temperature is called saturated solution.
☞Unsaturated solution:-A solution in which more quantity of solute can be dissolved without raising its temperature is called unsaturated solution.
SOLUBILITY
The maximum amount of a solute which can be dissolved in 100g of a solvent at a specified temperature is known as solubility of a solute in that solvent(at that temperature).☞Solubility of a solids in liquids usually increases on increasing the temperature.
what is a suspension and its characteristics
☞A suspension is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended
throughout the bulk of the medium .Eg:- chalk in water,smoke in the air
Characteristics
☞It is a Heterogeneous mixture in which the small particles of a solid are spread throughout a liquid without dissolving in it. Eg:- muddy water,chalk water
☞Size of solute particles 100nm in diameter.
☞A suspension can be separated by filtration.
☞Suspension are unstable,its particles settle down after some time.
☞It scatters a beam of light passing through out.
TYNDALL EFFECT
The scattering of light by colloidal particles is called Tyndall effect.
☞Size of solute particles 100nm in diameter.
☞A suspension can be separated by filtration.
☞Suspension are unstable,its particles settle down after some time.
☞It scatters a beam of light passing through out.
What is colloidal solution and its characteristics
COLLOIDS
☞IT is a kind of solution in which size of solute particles is intermediate between those in true solutions and those in suspensions.
☞IT is a kind of solution in which size of solute particles is intermediate between those in true solutions and those in suspensions.
characteristics
☞They appear to be Homogeneous but actually are heterogeneous.
☞Size of particles is between 1nm and 100nm.
☞Particles of a colloid can pass throughout fitter paper.
☞Colloids are stable,they do not separate out on keeping.
TYNDALL EFFECT
☞
CLASSIFICATION OF COLLOIDS
separation of the components of mixtures
I separate the mixture of two solids
☞To separate a mixture of sugar & sand. sugar is soluble in water but sand is insoluble in water
separating a mixture of salt and ammonium chloride
☞They can be separated by the process of sublimation.
☞Pure Ammonium chloride collects on the linear sides of the funnel in the form of a sublimate.
Experiment to obtain colored component(dye) from ink
Centrifugation:-
It is the method for separating the suspended particles of a substance from a liquid on which the mixture is spun or rotated at a high speed.
Principle:-
Denser particles are forced to the bottom and lighter particles sty at the top when spun rapidly.
Uses :-
Washing machines to squeeze out water from wet clothes.
☞In dairies and home to separate butter from cream
Chromatography :-
A technique of separating two or more dissolved solids which are present in a solution in very small quantities.
☞The separation is based on the fact that through two(or more)substances are soluble in the same solvent, their Solubilities may be different.
Purification By crystallization
The process of cooling a hot,concentrated solution of a substance to obtain crystals.
Step involved:-
☞Impure sample is dissolved in minimum amount of water to form solution.
☞Solution is filtered to remove impurities.
☞The clear solution is gently heated till a saturated solution is obtained.
☞Saturated solution is allowed to cool slowly.
☞Crystals of pure solid are formed.Impurities remain dissolved in the solution.
☞Crystals are filtered dried.
Separation of mixture of two liquid
Separation using separating funnel
☞A mixture of kerosene and water can be separated.
☞The liquid should be immiscible and should have different densities.
Separation by Distillation
The process of heating a liquid to form vapour, and then coiling the vapour to get back liquid.
Fractional Distillation
SEPARATION OF GASES IN THE AIR
The various gases of air are separated from one another by fractional distillation of liquid air.
☞The compressed by increasing the pressure and cooled by decreasing the temperature to get liquid air.
☞Liquid air is fed into a tall fractionating column and warmed up slowly.
Nitrogen(N) Argon(Ar) Oxygen(o)
B.p(-196c) B.p(-186c) B.p(-183c)
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