paper chromatography and separating immiscible liquids e. haniff

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Paper Chromatography and Separating immiscible liquids E. Haniff

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Page 1: Paper Chromatography and Separating immiscible liquids E. Haniff

Paper Chromatography and Separating immiscible liquids

E. Haniff

Page 2: Paper Chromatography and Separating immiscible liquids E. Haniff

Objectives

• Separate a mixture of different solutions using a given solvent (by difference of solubilities)

• Separate a mixture of immiscible liquids

Page 3: Paper Chromatography and Separating immiscible liquids E. Haniff

What are immiscible liquids?• Immiscible liquids are two liquids

which cannot be dissolved in one another

• They form two distinct layers

Page 4: Paper Chromatography and Separating immiscible liquids E. Haniff

Separating immiscible liquids

Page 5: Paper Chromatography and Separating immiscible liquids E. Haniff

Title: Separation of two immiscible liquids• Aim: To separate a mixture of oil

and water• Apparatus and materials:

Separating funnel with tap, water, oil and 3 containers

Page 6: Paper Chromatography and Separating immiscible liquids E. Haniff

Diagram:

Page 7: Paper Chromatography and Separating immiscible liquids E. Haniff

Method• The apparatus was set up as shown

in the diagram• The denser liquid at the bottom of the

separating funnel was withdrawn through the tap and collected in a container

• The container was then replaced with another and a small quantity of liquid was withdrawn (a mixture of the two right after the denser liquid was withdrawn

Page 8: Paper Chromatography and Separating immiscible liquids E. Haniff

Method continued…

• The container was then replaced again and the less dense liquid was allowed to run out and was collected.

• Observations were noted

Page 9: Paper Chromatography and Separating immiscible liquids E. Haniff

Observations

• Two separate layers were formed in the separating funnel.

• The oil was seen at the top layer and the water at the bottom layer

Page 10: Paper Chromatography and Separating immiscible liquids E. Haniff

Discussion• The separation of two immiscible

liquids is based on the principle that the two liquids do not mix and form two distinct layers

• The less dense liquid was the oil, which formed the top layer

• The denser liquid was the water which formed the bottom layer and was withdrawn first, allowing the separation of the two liquids

Page 11: Paper Chromatography and Separating immiscible liquids E. Haniff

Conclusion• The mixture of oil and water was

separated using a separating funnel• Oil and water are immiscible liquids

because they do not dissolve one another

Page 12: Paper Chromatography and Separating immiscible liquids E. Haniff

Application….• The principle of immiscibility of liquids

in some solvents is used in solvent extraction

• Solvent extraction is used to separate a component from a mixture by using two solvents.

• Two conditions have to be met:The component must be more soluble

in one solvent than in the otherThe two solvents must be immiscible

Page 13: Paper Chromatography and Separating immiscible liquids E. Haniff

For example…pg 75• To compare the solubility of iodine in

two solvents• Iodine is dissolved in water• The water is mixed with 1,1,1-

trichloroethane• The iodine goes into this solvent and

the water can be drained off in a separating funnel

Page 14: Paper Chromatography and Separating immiscible liquids E. Haniff

Another example

Page 15: Paper Chromatography and Separating immiscible liquids E. Haniff

Uses of solvent extraction• Good for removing organic molecules

from water• For example caffeine from tea or

coffee.• Caffeine is an organic compound

which is more soluble in an organic solvent which is immiscible with water.(Dichloromethane)

Page 16: Paper Chromatography and Separating immiscible liquids E. Haniff

Title: Paper Chromatography• Aim: To separate the components

of screened methyl orange• Apparatus and materials: filter

paper, beaker, capillary tube, test tube, screened methyl orange

Page 17: Paper Chromatography and Separating immiscible liquids E. Haniff

Diagram:

Page 18: Paper Chromatography and Separating immiscible liquids E. Haniff

Method:

• To a strip of filter paper, a capillary tube was used to place a small drop of methyl orange, close to the base of the paper

• A small volume of water was placed in a test tube or beaker

• The strip of filter paper was suspended so that it barely touched the solvent

Page 19: Paper Chromatography and Separating immiscible liquids E. Haniff

Method:

• It was left to stand for a while • Observations were recorded

Page 20: Paper Chromatography and Separating immiscible liquids E. Haniff

Observations

• The liquid moved up the filter paper• Distinct colours could be seen• The colour that moved the furthest up

the filter paper was…….

Page 21: Paper Chromatography and Separating immiscible liquids E. Haniff

Observations

Page 22: Paper Chromatography and Separating immiscible liquids E. Haniff

Discussion• Chromatography is a technique that

uses a stationary phase and a mobile phase

• The stationary phase is the filter paper in paper chromatography

• The mobile phase is the solvent that moves up the paper

• Chromatography can be used to separate minute quantities of substances.

Page 23: Paper Chromatography and Separating immiscible liquids E. Haniff

Discussion• Separation of the different

components occurs because each substance is soluble to different extents in the chosen solvent (the mobile phase)

• The more soluble component travels the furthest up the filter paper and the least soluble remains closer to the base

• Two colours were seen in screened methyl orange: two dyes a blue and a yellow

Page 24: Paper Chromatography and Separating immiscible liquids E. Haniff

Conclusion• Screened methyl orange contains two

components: a blue dye and a yellow dye

• The more soluble component appeared blue in colour

• The blue dye was more soluble in water

Page 25: Paper Chromatography and Separating immiscible liquids E. Haniff

Applications of chromatography

• Testing for trace contaminants in the environment

• Monitoring water quality and air quality

• Analyzing pure samples for trace contaminants (pharmaceutical industry)

• Quality control in food industry