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Flashcards in Clove Oil Deck (51):
1

Name given to this method of isolation?

Steam distillation

2

Why is steam distillation used?

Some components of clove oil have high boiling points and high temperatures would damage the molecules in oil

3

Why can't cloves be heated directly? And at what temp is it at

It would cause cloves to char and oil would be destroyed therefore steam is used and temp is kept slightly above 100 Celsius

4

Where is the steam produced?

Steam generator

5

What is the function of the safety tube?

Ensures there is no build up of pressure in steam generator

6

What would occur if there was no safety tube?

The pressure in steam generator would increase and therefore water would be pushed up safety tube

7

What is the purpose of the steam trap?

It traps the steam that has condensed to water

8

What would occur if steam trap was no present?

Flask with cloves would fill up with water from condensed steam

9

Why are whole cloves used in this experiment?

They contain the bud of the clove which is part with most oil

10

Name and chemical formula of oil found in cloves?

Eugenol, C10H12O2

11

What's the boiling point of eugenol?

254 degrees celsius

12

Why are the cloves harvested/picked before they flower?

Stage in which its richest in oil

13

Give a safety precaution

Wear gloves during exp - eugenol can burn skin

14

Describe steps used in extraction?

Set up apparatus as shown
Add whole cloves and warm water in pear shaped flask
Connect steam generator to rest of apparatus and heat to boiling point. Regulate heat so there is a constant supply of steam to pear shaped flask
Add anti bumping granules in steam generator
Leave for a few minutes
Collect distillate - pale milky appearance

15

What is the distillate of the experiment?

Emulsion [product of experiment]

16

What's an emulsion?

Mixture of immiscible liquids where tiny particles of one liquid are dispersed throughout the other, but not dissolved

17

Common emulsion found in everyday life?

Mayonnaise - em of oil in water

18

Appearance of emulsion?

Pale and milky

19

How do you remove the oil from the emulsion?

Solvent extraction

20

Name a suitable solvent for solvent extraction?

Cyclohexane

21

Why is cyclohexane suitable for solvent extraction

It will dissolve clove tuenoil but no other substances

22

Describe steps in solvent extraction

Add cyclohexane to emulsion in a sep funnel, where two liquids are "washed" - shaken for few minutes in stoppered funnel
Two liquids are separated into layers and water layer is discarded
Magnesium sulphate is added to organic solution and acts a drying agent and swirl conical flask
Pour into fluted paper in funnel which separated mg sulphate from oil and cyclohexane into clean dry flask
Evaporate cyclohexane in evaporating dish

23

What is meant by washing?

Extract the maximum amount of clove oil from emulsion

24

When the emulsion is "washed" what is observed?

Less milky, more clear solution

25

What is the purpose of adding anhydrous magnesium sulfate to organic solution?

Acts as a drying agent

26

How do you know enough magnesium sulphate is added?

Until powder settles at the bottom without forming clumps

27

Why is it necessary to remove magnesium sulphate from cyclohexane solution?

To remove any traces of oil from magnesium sulphate

28

How is magnesium sulphate removed?

By filtration and washing with cyclohexane

29

How is cyclohexane removed from clove oil?

Evaporation in evaporating dish/over water bath

30

Give two reasons why cannot heat directly with Bunsen burner to remove cyclohexane

Cyclohexane is flammable
Oil and cyclohexane could be evaporated together

31

Give two uses of clove oil

Flavouring foods
Pain relief

32

Name another substance that can be extracted with steam distillation

Orange oil from skin of oranges

33

Give a brief note explaining how steam distillation is used to extract oils from plant materials

Steam passes through plant material which forms a gaseous emulsion with oil in plant material. Hot emulsion is forced under pressure into Liebig condenser and converts gaseous emulsion into liquid and is extracted with organic solvent

34

What substance distilled across along with natural product?

Steam/h20

35

Identify safety feature of apparatus

Safety tube - ensures there's no pressure build up in safety generator
Air tight seals - no steam escapes

36

What is meant by Imiscible liquids

Do not dissolve in each other

37

How to calculate percentage yield?

pure mass organic liquid / plant material x100/1

38

What natural product did you extract in the school lab using steam distillation?

Eugenol

39

What substance distilled alongside the Eugenol?

Water

40

Name a technique that could be used to seperate the organic substance from the water

Solvent Extraction

41

Calculate percentage yield - which is actual yield and which is theoretical yield

actual yield - what was actually obtained
theoretical yield - you either work out, or its the other grams

42

What is the difference between a seperating funnel and and a dropping funnel?

S funnel - has a stopper
Dropping funnel - has no stopper

43

Why is a beaker always placed below seperating funnel

In case tap is left open, to collect solution

44

During solvent extraction, washing occurs and the tap is opened, why?

To release pressure of vaporised liquid inside the funnel

45

In solvent extraction, why is washing repeated?

In order to extract the maximum amount of oil from the emulsion

46

What is the purpose of adding the anhydrous magnesium sulphate during solvent extraction

To absorb the water from solution (oil of cloves - eugenol)

47

What is the purpose of fluted filter paper?

Speeds up filtration - the surface area of the filter paper in contact with the liquid is greater

48

What remains in filtered paper after filtration of magnesium sulfate from oil of cloves solution

Magensium sulphate

49

What is the structure of eugenol?

Benzene + 3 carbons with one double bond on second carbon. on top - OH, and then beside, OCH3

50

Why shouldn't you allow eugenol to come in contact with skin?

It has a burning effect on skin

51

Name a spectroscopic technique that could help confirm the identity of a sample of Eugenol

IR infrared