Practical 1
First, we measured out 18cm3 of 3m sulphuric acid into a boiling tube, then the boiling tube is put
into a beaker that has ice water in it and weighed out 3.4g of sodium dichromate to the acid in the
boiling tube and stir until dissolved completely and make sure that the solution is below 10 oC. After
it is cooled below 10oC add 2 to 3 drops of ethanol and stir it continue adding the ethanol slowly
until the mixture has turned from orange to green and the temperature rises, you have to add the
ethanol slowly so it the temperature doesn’t rise above 20 oC.
We the set up reflux apparatus with a 50cm 3 pear shaped flask and add some bumping granules to
the flask, then we poured the mixture into the same pear shaped flask and allow it to warm to room
temperature, next we added hot water into the beaker that the pear shaped flask is in and turn on
the Bunsen burner and leave the set up for 20 minutes and allow the apparatus to cool down, then
take the reflux apparatus from the beaker with water in and dry off the pear shaped flask
Then we set up the apparatus for distillation and add a few more bumping granules to the pear-
shaped flask, then we light the Bunsen burner and allowed the mixture to heat up again until in the
flask at the end of the condenser has a clear colourless liquid.
We then did some qualitative tests on the liquid to test if it's pure ethanoic acid. The first one is to
smell it and it should smell like vinegar. We then separated the distillate into 4 test tubes, we added
barium chloride into one and no white precipitate should form. To another one of the test tubes, we
added sodium carbonate which should result in a fizzing same as when we added magnesium to the
third test tube. Finally, we added methyl orange to the fourth and last test tube which should result
in a colour change.
Results
Test Result
Smell Smelt of Vinegar
Barium Chloride No White Participate
Sodium Carbonate Fizzes
Magnesium Fizzes
Methyl Orange Colour Change – Colourless to Orange
Yield
Total mass collected = 111.10-102.99 = 8.11
42%
Chemical reactions that where performed, why they work and how
different functional groups react.
Oxidisation
The oxidation of ethanol produces ethanoic acid (Ethanol (C₂H₆O) + [O] → Ethanal (C2H4O) + [O] →
Ethanoic Acid (CH₃COOH)) the ethanol is first partially oxidised with the sodium dichromate into
ethanal and then fully oxidised into ethanoic acid with excess of the oxidising agent, the reaction is
done under reflux so that when the ethanal is made it doesn’t escape so it can be fully oxidised. The
oxidation of ethanol involves the removal of a carbon to hydrogen bond and adds a double carbon to
oxygen bond to make an aldehyde then another carbon to oxygen bond is made which makes a
carboxylic acid (ethanoic acid).
, Practical 2
35ml of concentrated Nitric Acid is added to a round bottom flask, whilst stirring 40ml of cold
concentrated Sulphuric acid is added to the flask. IN an addition funnel 30ml of benzene is added,
while the nitric acid and Sulphuric acid mixture is being cooled in an ice bath the benzene is added
one drop at a time, whilst this is being done the temperature must remain below 55oC. The mixture
is then heated to 60oC for one hour, then the mixture is allowed to cool and is poured into a
separating funnel and the lower layer that contain the leftover acids is drained away to leave the
nitrobenzene. The layer still left in the separator funnel is then washed with water twice to get rid of
any of the left-over acids. Then to purify the nitrobenzene of the water and di/tri nitrated product
you carry out a distillation. After setting up the distillation apparatus heat the solution to around
208oC to collect the distillate which should be a cloudy white. To remove any left over water, add
calcium chloride and mix it up, allow the solution to go clear and filter off the calcium chloride which
then leaves a clear light yellow liquid which is nitrobenzene.
Results
Yield – 57%
Chemical reactions that where performed, why they work and how
different functional groups react for practical 2
Nitration of benzene which is an example of electrophilic aromatic substitution.
The nitration of benzene is a reaction called electrophilic substitution to form nitro benzene, the
benzene is mixed with nitric and sulphuric acid at a temperature no higher than 50 oC because it
could mean that one of the nitro functional groups onto the benzene ring. First the sulphuric acid
and nitric acid react to form a nitronium ion, hydrogen sulphate ion and a hydronium ion the
nitronium ion is an electrophile so is attracted to the electron dense ring of delocalised electrons and
two electrons from the delocalised ring form a bond with the nitronium ion which leaves the ring of
delocalised electrons broken and slightly positive. The hydrogen sulphate ion the donates two
electrons to the hydrogen that shares the same carbon that the nitro group is now bonded to which
breaks the hydrogen to carbon bond and the electrons that used to form that bond fix the
delocalised ring of electrons.
Importance of the conditions chosen
What would happen if we increased the temperature?
Practical 1
Reflux – if you increase the temperature of reflux too high to much liquid will be flowing down the
column leading to over condensation which could lead to the apparatus flooding.
Distillation – if we increased the temperature during the distillation of the mixture it would mean
that all the mixture would evaporate and not just the ethanoic acid meaning the distillation won't
separate like its meant to do.
Practical 2
If you overheat the reaction it will decrease the yield
Also, when adding the benzene to the acid solution if the temperature was increased above 55oC it
would mean that di and tri nitrobenzene will form which are explosive.
First, we measured out 18cm3 of 3m sulphuric acid into a boiling tube, then the boiling tube is put
into a beaker that has ice water in it and weighed out 3.4g of sodium dichromate to the acid in the
boiling tube and stir until dissolved completely and make sure that the solution is below 10 oC. After
it is cooled below 10oC add 2 to 3 drops of ethanol and stir it continue adding the ethanol slowly
until the mixture has turned from orange to green and the temperature rises, you have to add the
ethanol slowly so it the temperature doesn’t rise above 20 oC.
We the set up reflux apparatus with a 50cm 3 pear shaped flask and add some bumping granules to
the flask, then we poured the mixture into the same pear shaped flask and allow it to warm to room
temperature, next we added hot water into the beaker that the pear shaped flask is in and turn on
the Bunsen burner and leave the set up for 20 minutes and allow the apparatus to cool down, then
take the reflux apparatus from the beaker with water in and dry off the pear shaped flask
Then we set up the apparatus for distillation and add a few more bumping granules to the pear-
shaped flask, then we light the Bunsen burner and allowed the mixture to heat up again until in the
flask at the end of the condenser has a clear colourless liquid.
We then did some qualitative tests on the liquid to test if it's pure ethanoic acid. The first one is to
smell it and it should smell like vinegar. We then separated the distillate into 4 test tubes, we added
barium chloride into one and no white precipitate should form. To another one of the test tubes, we
added sodium carbonate which should result in a fizzing same as when we added magnesium to the
third test tube. Finally, we added methyl orange to the fourth and last test tube which should result
in a colour change.
Results
Test Result
Smell Smelt of Vinegar
Barium Chloride No White Participate
Sodium Carbonate Fizzes
Magnesium Fizzes
Methyl Orange Colour Change – Colourless to Orange
Yield
Total mass collected = 111.10-102.99 = 8.11
42%
Chemical reactions that where performed, why they work and how
different functional groups react.
Oxidisation
The oxidation of ethanol produces ethanoic acid (Ethanol (C₂H₆O) + [O] → Ethanal (C2H4O) + [O] →
Ethanoic Acid (CH₃COOH)) the ethanol is first partially oxidised with the sodium dichromate into
ethanal and then fully oxidised into ethanoic acid with excess of the oxidising agent, the reaction is
done under reflux so that when the ethanal is made it doesn’t escape so it can be fully oxidised. The
oxidation of ethanol involves the removal of a carbon to hydrogen bond and adds a double carbon to
oxygen bond to make an aldehyde then another carbon to oxygen bond is made which makes a
carboxylic acid (ethanoic acid).
, Practical 2
35ml of concentrated Nitric Acid is added to a round bottom flask, whilst stirring 40ml of cold
concentrated Sulphuric acid is added to the flask. IN an addition funnel 30ml of benzene is added,
while the nitric acid and Sulphuric acid mixture is being cooled in an ice bath the benzene is added
one drop at a time, whilst this is being done the temperature must remain below 55oC. The mixture
is then heated to 60oC for one hour, then the mixture is allowed to cool and is poured into a
separating funnel and the lower layer that contain the leftover acids is drained away to leave the
nitrobenzene. The layer still left in the separator funnel is then washed with water twice to get rid of
any of the left-over acids. Then to purify the nitrobenzene of the water and di/tri nitrated product
you carry out a distillation. After setting up the distillation apparatus heat the solution to around
208oC to collect the distillate which should be a cloudy white. To remove any left over water, add
calcium chloride and mix it up, allow the solution to go clear and filter off the calcium chloride which
then leaves a clear light yellow liquid which is nitrobenzene.
Results
Yield – 57%
Chemical reactions that where performed, why they work and how
different functional groups react for practical 2
Nitration of benzene which is an example of electrophilic aromatic substitution.
The nitration of benzene is a reaction called electrophilic substitution to form nitro benzene, the
benzene is mixed with nitric and sulphuric acid at a temperature no higher than 50 oC because it
could mean that one of the nitro functional groups onto the benzene ring. First the sulphuric acid
and nitric acid react to form a nitronium ion, hydrogen sulphate ion and a hydronium ion the
nitronium ion is an electrophile so is attracted to the electron dense ring of delocalised electrons and
two electrons from the delocalised ring form a bond with the nitronium ion which leaves the ring of
delocalised electrons broken and slightly positive. The hydrogen sulphate ion the donates two
electrons to the hydrogen that shares the same carbon that the nitro group is now bonded to which
breaks the hydrogen to carbon bond and the electrons that used to form that bond fix the
delocalised ring of electrons.
Importance of the conditions chosen
What would happen if we increased the temperature?
Practical 1
Reflux – if you increase the temperature of reflux too high to much liquid will be flowing down the
column leading to over condensation which could lead to the apparatus flooding.
Distillation – if we increased the temperature during the distillation of the mixture it would mean
that all the mixture would evaporate and not just the ethanoic acid meaning the distillation won't
separate like its meant to do.
Practical 2
If you overheat the reaction it will decrease the yield
Also, when adding the benzene to the acid solution if the temperature was increased above 55oC it
would mean that di and tri nitrobenzene will form which are explosive.
