extraction of limonene

Question 1

what does orange oil contain ?

Answer 1

• limonene

Question 2

where can one extract limonene from ?

Answer 2

• from orange peel

Question 3

where is limonene used in ?

Answer 3

• food manufacture,medicines and cleaning products

Question 4

what is limonene at room temperature ?

Answer 4

• it is a colourless oily liquid that smells of oranges

Question 5

how can limonene be extracted ?

Answer 5

• from an orange peel by distilling water a water/oil mixture from a mixture of water an orange peel

Question 6

what is the aim of the experiment ?

Answer 6

• to extract limonene from orange peel by distillation and test for unsaturation

Question 7

draw and label the apparatus via distillation

Answer 7

find in powerpoint or textbook

Question 8

draw limonene in skeletal formulae

Answer 8

find on phone :)

Question 9

name the skeletal formulae according to IUPAC naming

Answer 9

find on phone :)

Question 10

draw and label the apparatus via reflux

Answer 10

find on phone :)

Question 11

list the method of the stage 1 experiment

Answer 11

1. cut up orange peel into small pieces (<0.5cm) and 1/3 rd fill the round-bottom flask
2. add enough distilled water to the flask to just cover the peel
3. set up the apparatus as shown above
4. very gently heat the solution using a half-blue flame , for about 5 minutes, moving the flame up and down the flask
   –> minimise the boiling of the water at this stage and avoid the burning the orange
   ( this can also be achieved by using a gauze )
5. after the 5 minutes , heat the tube more strongly to distille off the water/orange oil mixture until you have distilled off half the mixture
6. measure and record the temperature of the water/oil vapour

Question 12

list the method of the stage 2 experiment

Answer 12

distillation of orange oil from orange peel

Question 13

what is stage 2 of the method of the experiment ?

Answer 13

1. allow the distillate to stand for 1-2 minutes until a cloudy layer has separated to the top of the beaker - this is called the upper organic layer and contains limonene
2. carefully smell the solution in the test tube
3. carefully pipette off the upper layer and divide it evenly between 2 test ubes
4. add one drop of bromine water to the 1st tube and 1 drop of acidified potassium maganate (VII) to the 2nd tube . shake the tubes side to side and observe any colour changes
5. repeat step 3 and 4 with cyclohexane then cyclohexene
6. alternatively carry out steps 3-5 in a dropping tile

Question 14

how many carbon-carbon double bonds will limonene have ?

Question 15

what affect does a ring in the structure have on the number of hydrogens in the compound?

Question 16

limonene is a chiral compound. Find out what this means and the different properties of the two versions of limonene. Draw the two isomers.