Flashcards in Clove Oil Deck (51):
Name given to this method of isolation?
Why is steam distillation used?
Some components of clove oil have high boiling points and high temperatures would damage the molecules in oil
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
Where is the steam produced?
What is the function of the safety tube?
Ensures there is no build up of pressure in steam generator
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
What is the purpose of the steam trap?
It traps the steam that has condensed to water
What would occur if steam trap was no present?
Flask with cloves would fill up with water from condensed steam
Why are whole cloves used in this experiment?
They contain the bud of the clove which is part with most oil
Name and chemical formula of oil found in cloves?
What's the boiling point of eugenol?
254 degrees celsius
Why are the cloves harvested/picked before they flower?
Stage in which its richest in oil
Give a safety precaution
Wear gloves during exp - eugenol can burn skin
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
What is the distillate of the experiment?
Emulsion [product of experiment]
What's an emulsion?
Mixture of immiscible liquids where tiny particles of one liquid are dispersed throughout the other, but not dissolved
Common emulsion found in everyday life?
Mayonnaise - em of oil in water
Appearance of emulsion?
Pale and milky
How do you remove the oil from the emulsion?
Name a suitable solvent for solvent extraction?
Why is cyclohexane suitable for solvent extraction
It will dissolve clove tuenoil but no other substances
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
What is meant by washing?
Extract the maximum amount of clove oil from emulsion
When the emulsion is "washed" what is observed?
Less milky, more clear solution
What is the purpose of adding anhydrous magnesium sulfate to organic solution?
Acts as a drying agent
How do you know enough magnesium sulphate is added?
Until powder settles at the bottom without forming clumps
Why is it necessary to remove magnesium sulphate from cyclohexane solution?
To remove any traces of oil from magnesium sulphate
How is magnesium sulphate removed?
By filtration and washing with cyclohexane
How is cyclohexane removed from clove oil?
Evaporation in evaporating dish/over water bath
Give two reasons why cannot heat directly with Bunsen burner to remove cyclohexane
Cyclohexane is flammable
Oil and cyclohexane could be evaporated together
Give two uses of clove oil
Name another substance that can be extracted with steam distillation
Orange oil from skin of oranges
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
What substance distilled across along with natural product?
Identify safety feature of apparatus
Safety tube - ensures there's no pressure build up in safety generator
Air tight seals - no steam escapes
What is meant by Imiscible liquids
Do not dissolve in each other
How to calculate percentage yield?
pure mass organic liquid / plant material x100/1
What natural product did you extract in the school lab using steam distillation?
What substance distilled alongside the Eugenol?
Name a technique that could be used to seperate the organic substance from the water
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
What is the difference between a seperating funnel and and a dropping funnel?
S funnel - has a stopper
Dropping funnel - has no stopper
Why is a beaker always placed below seperating funnel
In case tap is left open, to collect solution
During solvent extraction, washing occurs and the tap is opened, why?
To release pressure of vaporised liquid inside the funnel
In solvent extraction, why is washing repeated?
In order to extract the maximum amount of oil from the emulsion
What is the purpose of adding the anhydrous magnesium sulphate during solvent extraction
To absorb the water from solution (oil of cloves - eugenol)
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
What remains in filtered paper after filtration of magnesium sulfate from oil of cloves solution
What is the structure of eugenol?
Benzene + 3 carbons with one double bond on second carbon. on top - OH, and then beside, OCH3
Why shouldn't you allow eugenol to come in contact with skin?
It has a burning effect on skin