Evidence of practical work
Our method
1.A balance was used to weigh 2g of salicylic acid which was placed into a conical flask
Using a flume cupboard 5.0ml of acetic anhydride was added to the acid
5 drops of 85% of phosphoric acid were also added to the flask.
2.The flask was clamped above a water bath , the mixture was heated until the salicyclic
acid and the mixtured was then kepted in the water in the water bath for 10 mintues
3.while the flask was kept in the water bath 2ml of distilled water was added this then inturn
decompused the acetic acid
4.After a minute, the mixture was removed from the water bath, 20ml of distilled water was
then added.
5. The flask was allowed to cool at room temperature crystals will start to form . The mixture
was placed in a ice water bath to spead up the crystilation
6. A buchner funnel on a vacuum flask connected to a water aspirator.The filter paper was
placed on the bottom of the flask and damped with distilled water.
7.The aspirator was turned on and the crystal slurry was transferred into the funnel and then
washed with 5ml distilled water .
, 8.The aspirin was then dryed in a oven over a period of 3 days
9. The dryed amount was then weighted and a calculation of yield was calculated.
Results
Ar of salicylic acid= 138
Ar of aspirin= 180
138:180
1:1.3
2g= 2.6g
2.60-1.14=1.56/2.60=0.6x100=60%
Risk assessment
Hazard Risk Control measure Emergency action
acetic anhydride Corrosive chemical Eye protection Eye Contact
Eye and skin Wear gloves when Rinse immediately
damage handling with plenty of water,
Try to use the low also under the
amount eyelids, for at least
Well ventilated area 15 minutes.
. Skin Contact Wash
off immediately with
plenty of water for at
least 15 minutes.
Immediate medical
attention is required.
phosphoric acid Eye, inhelation and Eye protection Eye Contact
skin irritation Wear gloves when Rinse immediately
handling with plenty of water,
Well ventilated area also under the
eyelids, for at least
15 minutes.
. Skin Contact Wash
off immediately with
plenty of water for at
least 15 minutes.
Immediate medical
attention is required.
salicylic acid Eye damage and Eye protection Eye Contact
skin damage Wear gloves when Rinse immediately
handling with plenty of water,
Well ventilated area also under the
should limit your eyelids, for at least
time around it. 15 minutes.
. Skin Contact Wash
Our method
1.A balance was used to weigh 2g of salicylic acid which was placed into a conical flask
Using a flume cupboard 5.0ml of acetic anhydride was added to the acid
5 drops of 85% of phosphoric acid were also added to the flask.
2.The flask was clamped above a water bath , the mixture was heated until the salicyclic
acid and the mixtured was then kepted in the water in the water bath for 10 mintues
3.while the flask was kept in the water bath 2ml of distilled water was added this then inturn
decompused the acetic acid
4.After a minute, the mixture was removed from the water bath, 20ml of distilled water was
then added.
5. The flask was allowed to cool at room temperature crystals will start to form . The mixture
was placed in a ice water bath to spead up the crystilation
6. A buchner funnel on a vacuum flask connected to a water aspirator.The filter paper was
placed on the bottom of the flask and damped with distilled water.
7.The aspirator was turned on and the crystal slurry was transferred into the funnel and then
washed with 5ml distilled water .
, 8.The aspirin was then dryed in a oven over a period of 3 days
9. The dryed amount was then weighted and a calculation of yield was calculated.
Results
Ar of salicylic acid= 138
Ar of aspirin= 180
138:180
1:1.3
2g= 2.6g
2.60-1.14=1.56/2.60=0.6x100=60%
Risk assessment
Hazard Risk Control measure Emergency action
acetic anhydride Corrosive chemical Eye protection Eye Contact
Eye and skin Wear gloves when Rinse immediately
damage handling with plenty of water,
Try to use the low also under the
amount eyelids, for at least
Well ventilated area 15 minutes.
. Skin Contact Wash
off immediately with
plenty of water for at
least 15 minutes.
Immediate medical
attention is required.
phosphoric acid Eye, inhelation and Eye protection Eye Contact
skin irritation Wear gloves when Rinse immediately
handling with plenty of water,
Well ventilated area also under the
eyelids, for at least
15 minutes.
. Skin Contact Wash
off immediately with
plenty of water for at
least 15 minutes.
Immediate medical
attention is required.
salicylic acid Eye damage and Eye protection Eye Contact
skin damage Wear gloves when Rinse immediately
handling with plenty of water,
Well ventilated area also under the
should limit your eyelids, for at least
time around it. 15 minutes.
. Skin Contact Wash
