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2 The Different Separation Techniques are as follows: ~ Magnetic attraction ~ Filtration ~ Evaporation ~ Distillation ~ Chromatography ~ Sublimation ~ Using Separating Funnel Note: The physical methods used will depend on the nature of its constituents. The Different Separation Techniques are as follows: ~ Magnetic attraction ~ Filtration ~ Evaporation ~ Distillation ~ Chromatography ~ Sublimation ~ Using Separating Funnel Note: The physical methods used will depend on the nature of its constituents.

3 This process is used to separate magnetic objects e.g. iron, steel, nickel, cobalt from non-magnetic ones in a mixture, e.g. separating iron filings and sulfur powder. Magnetic Attraction

4 1. Electromagnets are used to remove steel and iron scrap at the junk-yard. 2. In hospitals, magnets are often used to remove iron splinters from a patient’s eyes. Applications of Magnetic Attraction

5 Filtration This process is used to separate insoluble solids from the liquid in a solid-liquid mixture, e.g. separating sand from a mixture of sand and water. The insoluble solid that remains on the filter paper is called residue. The liquid that passes through is called the filtrate.

6 air filters in air conditioners remove solid impurities from air hair in our nostrils trap the dust particles that we breathe in and allow only clean air to pass through oil and air filters in cars remove solid impurities found in engine oil and air air filters in air conditioners remove solid impurities from air hair in our nostrils trap the dust particles that we breathe in and allow only clean air to pass through oil and air filters in cars remove solid impurities found in engine oil and air Applications of Filtration

7 Evaporation to dryness is a process used to separate a dissolved solid that does not decompose on heating, e.g. common salt from a salt solution Evaporation to dryness is a process used to separate a dissolved solid that does not decompose on heating from a solution, e.g. common salt from a salt solution Evaporation to dryness

8 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. Evaporating a Solution

9 drying wet clothes drying hair with a hair-dryer obtaining common salt from the sea drying wet clothes drying hair with a hair-dryer obtaining common salt from the sea Applications of Evaporation

10 Distillation is a process used to separate a liquid(solvent) from a solid-liquid solution or liquid-liquid solution. Pure water can be distilled from a soft drinks Distillation is a process used to separate a liquid(solvent) from a solid-liquid solution or liquid-liquid solution. Pure water can be distilled from a soft drinks Distillation

11 Distillation

12 This process can be used to separate miscible liquids with different boiling points where the liquid with the lower boiling point will vaporize first We can use this method to separate alcohol and water This process can be used to separate miscible liquids with different boiling points where the liquid with the lower boiling point will vaporize first We can use this method to separate alcohol and water Fractional Distillation

13 Fractional Distillation

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18 Chromatography is a process used to separate the different components in a liquid or gaseous mixture. Chromatography is a process used to separate the different components in a liquid or gaseous mixture. For example it can be used to: 1.Separate the different coloured components that make up black ink 2.Detect tiny amounts of drugs or certain other chemicals in urine samples Chromatography is a process used to separate the different components in a liquid or gaseous mixture. Chromatography is a process used to separate the different components in a liquid or gaseous mixture. For example it can be used to: 1.Separate the different coloured components that make up black ink 2.Detect tiny amounts of drugs or certain other chemicals in urine samples Chromatography

19 1.Apply a small but concentrated spot of the solution on a piece of chromatography paper. 2.Suspend the chromatography paper in a beaker or boiling tube of solvent with the spot above the level of the solvent. 1.Apply a small but concentrated spot of the solution on a piece of chromatography paper. 2.Suspend the chromatography paper in a beaker or boiling tube of solvent with the spot above the level of the solvent. Paper Chromatography

20 Paper Chromatography Paper 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 Chromatography Paper 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.

21 Paper Chromatography 4.As the solvent travels up the paper, the mixture is separated into its respective components. A chromatogram of the separated components is obtained. Paper Chromatography 4.As the solvent travels up the paper, the mixture is separated into its respective components. A chromatogram of the separated components is obtained.

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25 Applications Analysing ink dyes for forgery casesAnalysing ink dyes for forgery cases Analysing food dyes to ensure thatAnalysing food dyes to ensure that only permitted colourings are used only permitted colourings are used in foodstuffs in foodstuffs Checking whether pesticides onChecking whether pesticides on vegetables exceed safe levels vegetables exceed safe levels Detecting trace levels of drugs inDetecting trace levels of drugs in urine samples urine samples Applications Analysing ink dyes for forgery casesAnalysing ink dyes for forgery cases Analysing food dyes to ensure thatAnalysing food dyes to ensure that only permitted colourings are used only permitted colourings are used in foodstuffs in foodstuffs Checking whether pesticides onChecking whether pesticides on vegetables exceed safe levels vegetables exceed safe levels Detecting trace levels of drugs inDetecting trace levels of drugs in urine samples urine samples

26 Advantage Able to obtain results quick.Able to obtain results quick. Only a small amount of sample is required for chromatography.Only a small amount of sample is required for chromatography. Advantage Able to obtain results quick.Able to obtain results quick. Only a small amount of sample is required for chromatography.Only a small amount of sample is required for chromatography.

27 Using a Separating Funnel two immiscible liquids A separating funnel can be used to separate two immiscible liquids, such as oil and water.

28 Sublimation solid which sublimes when heated This method is used to separate a solid which sublimes when heated. Common substances which can sublime include iodine, dry ice, mothballs (napthalene) and ammonium chloride. A mixture containing ammonium chloride and sodium chloride can be separated using this method.

29 Techniques in obtaining Pure Water from Sea Water Method 1 Distillation of sea water. Method 2 Desalination of sea water by Reverse Osmosis

30 Reverse Osmosis

31 Reverse Osmosis not the dissolved saltsThe partially permeable membrane in the diagram normally allows water to pass through easily but not the dissolved salts in the sea water. This flow of water is called osmosis.

32 Reverse Osmosis When a high pressure (about 26 times more than atmospheric pressure) is applied on sea water, the direction of flow reverses. It means water starts flowing from the sea water side to the fresh water side of the membrane. This process is called reverse osmosis, thus allowing fresh water to be obtained from sea water.