Simple techniques of separating Simple techniques of separating mixturesmixtures

AKM B- FormAKM B- Form

Lesson PlanLesson Plan

To see the lesson plan ,please click on the To see the lesson plan ,please click on the following linkfollowing link

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AudienceAudience

Grade: 9Grade: 9 Age Group: 15 yearsAge Group: 15 years Learner profiles –Different abilities Learner profiles –Different abilities

[intelligent, mediocre and slow learners][intelligent, mediocre and slow learners] Their learning styles are differentTheir learning styles are different

Learning ObjectivesLearning Objectives

By the end of this session:By the end of this session: Students will be able to select the appropriate Students will be able to select the appropriate method to separate the given mixtures based upon method to separate the given mixtures based upon the information available about the components of the information available about the components of the mixture.the mixture.Students will understand the following terms: Students will understand the following terms: sedimentation & decantation, filtration, evaporation, sedimentation & decantation, filtration, evaporation, distillation and crystallization.distillation and crystallization.Students will develop skills of using various Students will develop skills of using various techniques to separate mixtures.techniques to separate mixtures.

Sedimentation and decantationSedimentation and decantation

Separating an insoluble solid/liquid mixture.Separating an insoluble solid/liquid mixture. Let us see how we can separate a mixture of Let us see how we can separate a mixture of

sand and water.sand and water.

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FiltrationFiltration

We will see now how we can separate a We will see now how we can separate a mixture of sulphur and water.mixture of sulphur and water.

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EvaporationEvaporation

Separating a solute from a solute/solvent Separating a solute from a solute/solvent mixture mixture

This method is used to separate a solid solute This method is used to separate a solid solute from a solventfrom a solvent

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DistillationDistillation

During evaporation or boiling, the liquid During evaporation or boiling, the liquid solvent is lost to the air. If the solvent is solvent is lost to the air. If the solvent is important it can be separated from the mixture important it can be separated from the mixture using a process called distillation.using a process called distillation.

DistillationDistillation

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CrystallisationCrystallisation

To separate a solute from its solvent, we heat To separate a solute from its solvent, we heat the solution gently. The solvent evaporates and the solution gently. The solvent evaporates and the concentration of the solute rises until the the concentration of the solute rises until the solution is saturated. If the heat is removed solution is saturated. If the heat is removed this at this time and the solution is left to cool, this at this time and the solution is left to cool, the solid will form crystals.the solid will form crystals.

Let us see this picture Let us see this picture

Crystallisation Crystallisation

Copper sulphate crystals can be obtained from its Copper sulphate crystals can be obtained from its solution by crystallization process.solution by crystallization process.

SublimationSublimation

When a sublimable substance is mixed with other When a sublimable substance is mixed with other substances which do not sublime, separation by substances which do not sublime, separation by heating is possible.heating is possible.

Sublimable substances are Iodine crystals, Sublimable substances are Iodine crystals, Ammonium chloride and camphor.Ammonium chloride and camphor.

They change directly into gas when heated and They change directly into gas when heated and change back to solid on cooling, without changing to change back to solid on cooling, without changing to the intermediate liquid state. the intermediate liquid state.

SublimationSublimation

We will see how can we separate a mixture of We will see how can we separate a mixture of ammonium chloride and sand. ammonium chloride and sand.

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Separating FunnelSeparating Funnel

When two immiscible liquids are mixed When two immiscible liquids are mixed together they eventually form layers, if left to together they eventually form layers, if left to stand.The less dense liquid forms a layer stand.The less dense liquid forms a layer above the more dense liquid.above the more dense liquid.

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Separation of two immiscible liquids Separation of two immiscible liquids using a seaparting funnelusing a seaparting funnel

Fractional DistillationFractional Distillation

Two miscible liquids with quite close boiling Two miscible liquids with quite close boiling points, such as water(100points, such as water(10000C) and ethanol C) and ethanol (78(7800C) can be separated by fractional C) can be separated by fractional distillation.distillation.

The separation occurs in the fractionating The separation occurs in the fractionating coulmn.This is filled with glass beads. During coulmn.This is filled with glass beads. During the fractionating process the liquids condense the fractionating process the liquids condense and evaporate from the beads many times.and evaporate from the beads many times.

Fractional DistillationFractional Distillation

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ChromatographyChromatography

A pure dye contains only one colour.Black ink A pure dye contains only one colour.Black ink is made from two or more coloured dyes.is made from two or more coloured dyes.

Separating substances like this is called Separating substances like this is called chromatography.chromatography.

The pattern of colours you get is called a The pattern of colours you get is called a chromatogram.chromatogram.

Paper chromatographyPaper chromatography

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Spreading at different speedsSpreading at different speeds

Chromatography is used to split up a mixture Chromatography is used to split up a mixture of substances that dissolve in the same of substances that dissolve in the same liquid.The substances spread across the paper liquid.The substances spread across the paper at different speeds.at different speeds.

Brown ink is made from a mixture of Brown ink is made from a mixture of yellow,blue and red inks.They can also be yellow,blue and red inks.They can also be separated by paper chromatography.separated by paper chromatography.

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Centrifugation/ChurningCentrifugation/Churning

Centrifugation is the method of separating Centrifugation is the method of separating solids from a liquid where the mixture is solids from a liquid where the mixture is homogeneous. The sedimentation of homogeneous. The sedimentation of suspended particles in a liquid takes place very suspended particles in a liquid takes place very slowly. The mixture is taken in two specially slowly. The mixture is taken in two specially designed test tubes known as the centrifuge designed test tubes known as the centrifuge tubes. They are placed in two separate holders. tubes. They are placed in two separate holders. The holders are then rotated rapidly with the The holders are then rotated rapidly with the help of a handle.help of a handle.

Centrifugation/ChurningCentrifugation/Churning

After some time the rotation is stopped and the After some time the rotation is stopped and the centrifuge tubes are taken out. It is seen that centrifuge tubes are taken out. It is seen that solid particles have settled down at the bottom solid particles have settled down at the bottom of the tubes. The supernatant liquid above the of the tubes. The supernatant liquid above the solid is collected by decantation.solid is collected by decantation.

If the density of solid is lighter than liquid ,it If the density of solid is lighter than liquid ,it comes in the upper layer.comes in the upper layer.

These days electric churners are used.These days electric churners are used.

ApplicationsApplications

It is used forIt is used for Separating cream from milk and butter from Separating cream from milk and butter from

curd in dairies or at home.curd in dairies or at home. In washing machines to squeezing out water In washing machines to squeezing out water

from wet clothes.from wet clothes. In diagnostic laboratories for testing In diagnostic laboratories for testing

blood/urine.blood/urine.

Electric churner and SeparationElectric churner and Separation

By Solvent extractionBy Solvent extraction It is the process of dissolving one of the It is the process of dissolving one of the

components in a particular liquid either water components in a particular liquid either water or any other solvent in which it gets dissolved or any other solvent in which it gets dissolved and the other component does not dissolve.and the other component does not dissolve.

For example , a mixture of iron filings and For example , a mixture of iron filings and sulphur is separated by using carbon disulphide sulphur is separated by using carbon disulphide as solvent.as solvent.

A mixture of sodium chloride and chalk can A mixture of sodium chloride and chalk can also be separated by using water as the solvent also be separated by using water as the solvent for sodium chloride.for sodium chloride.

Home AssignmentHome Assignment

For assignment on “Simple techniques of For assignment on “Simple techniques of Separation of mixtures", click on the link Separation of mixtures", click on the link given below.given below.

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ReferencesReferences

Google Image: Google Image: www.google.co.in for images for images Meta: Meta: www.ixquick.com for graphics and information for graphics and information http://www.youtube.com/watch?v=sBCLafMPVt8 for Sedimentation & for Sedimentation &

decantationdecantation http://www.youtube.com/watch?v=Q0s71cjCNWs for Filtration for Filtration http://www.youtube.com/watch?v=t2ZjWJsgGLo for Evaporationwww.youtube.com/watch?v=t2ZjWJsgGLo for Evaporation http://www.youtube.com/watch?v=xxNfJLMNS4E for Distillationhttp://www.youtube.com/watch?v=xxNfJLMNS4E for Distillation http://www.youtube.com/watch?v=W6hwOG7Dzf8 for Sublimationhttp://www.youtube.com/watch?v=W6hwOG7Dzf8 for Sublimation http://www.youtube.com/watch?v=vonoRZhWBvY for Fractional http://www.youtube.com/watch?v=vonoRZhWBvY for Fractional

distillationdistillation http://www.youtube.com/watch?v=Uw7LCwMmOu8 for Chromatographyhttp://www.youtube.com/watch?v=Uw7LCwMmOu8 for Chromatography

AcknowledgementAcknowledgement

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