text by mrs teo video clips taken from school video repository

Text by Mrs TeoVideo clips taken from school video repository

TheThe Different Separation Techniques Different Separation Techniques are as follows:are as follows:

• Magnetic attractionMagnetic attraction

• FiltrationFiltration

• EvaporationEvaporation

• CrystallisationCrystallisation

• DistillationDistillation

• ChromatographyChromatography

Note: Note: The physical method used will The physical method used will depend on the nature of the constituents.depend on the nature of the constituents.

TheThe Different Separation Techniques Different Separation Techniques are as follows:are as follows:

• Magnetic attractionMagnetic attraction

• FiltrationFiltration

• EvaporationEvaporation

• CrystallisationCrystallisation

• DistillationDistillation

• ChromatographyChromatography

Note: Note: The physical method used will The physical method used will depend on the nature of the constituents.depend on the nature of the constituents.

• used used to separate to separate magneticmagnetic materials,materials, e.g. iron, steel, e.g. iron, steel, nickel, cobalt nickel, cobalt from from non-non-magneticmagnetic ones in a mixture ones in a mixture

e.g. separating iron filings e.g. separating iron filings from sulphur powder.from sulphur powder.

Magnetic AttractionMagnetic Attraction

1.1.ElectromagnetsElectromagnets are are used to used to removeremove steel and iron steel and iron scrapscrap at the junk-yard.at the junk-yard.

Applications of Magnetic Applications of Magnetic AttractionAttraction

2.2. In hospitals, In hospitals, magnetsmagnets are often are often used used to to remove iron splintersremove iron splinters from a patient’s eyes.patient’s eyes.

Using a Separating FunnelUsing a Separating Funnel

• can be used to can be used to separate separate two two

immiscible liquidsimmiscible liquids,, such as such as oiloil

and waterand water..

Filtration• used to separate an insoluble solid

from

(i) a liquid in a solid-liquid mixture

e.g. sand from a mixture of sand and water or(ii) a soluble solide.g. calcium carbonate from mixture of it and copper(II) sulphate.

Filtration

• insoluble solid that remains on the

filter paper - residueresidue.

• liquid that passes through- filtratefiltrate.

• hair in our nostrils

trap the dust particles that we trap the dust particles that we breathe in and allow only clean air to breathe in and allow only clean air to pass throughpass through

• air filters in air conditioners

remove solid impurities from airremove solid impurities from air

• oil and air filters in cars

remove solid impurities found in remove solid impurities found in engine oil and airengine oil and air

• hair in our nostrils

trap the dust particles that we trap the dust particles that we breathe in and allow only clean air to breathe in and allow only clean air to pass throughpass through

• air filters in air conditioners

remove solid impurities from airremove solid impurities from air

• oil and air filters in cars

remove solid impurities found in remove solid impurities found in engine oil and airengine oil and air

Applications of FiltrationApplications of Filtration

• used to used to separate a dissolved solidseparate a dissolved solid that that does notdoes not decomposedecompose on heating on heating from a solution,,

e.g. common salt from a salt solution.e.g. common salt from a salt solution.

• used to used to separate a dissolved solidseparate a dissolved solid that that does notdoes not decomposedecompose on heating on heating from a solution,,

e.g. common salt from a salt solution.e.g. common salt from a salt solution.

Evaporation to Evaporation to drynessdryness

1. Pour the solution into an evaporating dish.

2. Heat the solution to dryness to evaporate away the solvent, leaving behind the solute.

3. Make the Bunsen flame smaller when almost all the solvent has been evaporated away to reduce spitting.

1. Pour the solution into an evaporating dish.

2. Heat the solution to dryness to evaporate away the solvent, leaving behind the solute.

3. Make the Bunsen flame smaller when almost all the solvent has been evaporated away to reduce spitting.

Procedure of Evaporating a Procedure of Evaporating a

SolutionSolution

• drying wet clothes drying wet clothes

• drying hair with a hair-dryerdrying hair with a hair-dryer

• obtaining common salt from the obtaining common salt from the seasea

• drying wet clothes drying wet clothes

• drying hair with a hair-dryerdrying hair with a hair-dryer

• obtaining common salt from the obtaining common salt from the seasea

Applications of EvaporationApplications of Evaporation

• process to obtain a solid that decomposes on heating from its solution.

• e.g. sugar from sugar solution and copper(II) sulphate crystals from copper(II) sulphate solution

• process to obtain a solid that decomposes on heating from its solution.

• e.g. sugar from sugar solution and copper(II) sulphate crystals from copper(II) sulphate solution

CrystallisatioCrystallisationn

• process used to separate a liquid (solvent) from a solid-liquid solution or liquid-liquid solution.

• e.g. pure water can be distilled from soft drinks

• process used to separate a liquid (solvent) from a solid-liquid solution or liquid-liquid solution.

• e.g. pure water can be distilled from soft drinks

DistillationDistillation

Distillation

• process can be used to separate miscible liquids with different boiling points

• liquid with lower boiling point will vaporize first

• e.g. to separate alcohol and water

• process can be used to separate miscible liquids with different boiling points

• liquid with lower boiling point will vaporize first

• e.g. to separate alcohol and water

Fractional DistillationFractional Distillation

• oil refineries - separating the various components of crude oil or petroleum

• industries supplying oxygen to hospitals, shipyards, etc – separating the components of air

Industrial Applications of Industrial Applications of Fractional Fractional DistillationDistillation

Fractional Distillation

1. to separate the different 1. to separate the different colouredcoloured components that make up components that make up black ink black ink

2.to detect 2.to detect tiny amounts of drugstiny amounts of drugs or certain other chemicals in or certain other chemicals in urine urine samplessamples..

1. to separate the different 1. to separate the different colouredcoloured components that make up components that make up black ink black ink

2.to detect 2.to detect tiny amounts of drugstiny amounts of drugs or certain other chemicals in or certain other chemicals in urine urine samplessamples..

Paper Chromatography• process used to separate the

different components in a liquid mixture

For example it can be usedFor example it can be used

1. Apply a small but 1. Apply a small but concentratedconcentratedspot of the solution on a piece spot of the solution on a piece of chromatography paper.of chromatography paper.

2. Suspend the 2. Suspend the chromatographychromatographypaper in a beaker or boiling paper in a beaker or boiling tube of solvent with the spot tube of solvent with the spot above the level of the solvent.above the level of the solvent.

1. Apply a small but 1. Apply a small but concentratedconcentratedspot of the solution on a piece spot of the solution on a piece of chromatography paper.of chromatography paper.

2. Suspend the 2. Suspend the chromatographychromatographypaper in a beaker or boiling paper in a beaker or boiling tube of solvent with the spot tube of solvent with the spot above the level of the solvent.above the level of the solvent.

Paper ChromatographyPaper Chromatography

Paper ChromatographyPaper Chromatography

3. Separation takes place because some components of the liquid mixture travel at a faster pace than other components on the paper or any other absorbent material.

Paper ChromatographyPaper Chromatography

3. Separation takes place because some components of the liquid mixture travel at a faster pace than other components on the paper or any other absorbent material.

Paper ChromatographyPaper Chromatography

3. As the solvent travels up the paper, the mixture is separated into its respective components.

A chromatogram of the separated components is obtained.

Paper ChromatographyPaper Chromatography

3. As the solvent travels up the paper, the mixture is separated into its respective components.

A chromatogram of the separated components is obtained.

Applications

•analysing ink dyes for forgery analysing ink dyes for forgery

casescases

•analysing food dyes to ensure analysing food dyes to ensure that that

only permitted colourings are only permitted colourings are used used

in foodstuffsin foodstuffs

•checking whether pesticides on

vegetables exceed safe levels

•detecting trace levels of drugs detecting trace levels of drugs in in urine samples urine samples

Applications

•analysing ink dyes for forgery analysing ink dyes for forgery

casescases

•analysing food dyes to ensure analysing food dyes to ensure that that

only permitted colourings are only permitted colourings are used used

in foodstuffsin foodstuffs

•checking whether pesticides on

vegetables exceed safe levels

•detecting trace levels of drugs detecting trace levels of drugs in in urine samples urine samples

The End

ACE Suggestion

1. Production of whisky by distillation of barley mash

ACE Suggestion

2. Commercial Production of sodium chloride by:(i) Mining

(ii) Evaporation of sea water