Unit 4: Laboratory Techniques and their Applica9on
C: Explore manufacturing techniques and tes9ng methods for an organic solid
Aim
The aim of this prac9cal was to be able to explore manufacturing techniques and tes9ng methods of
organic solids. We were assigned with the task with synthesising aspirin. Aspirin has medicinal
proper9es such as pain relief, fever reducer and is also a swelling reducing drug (NSAID). The most
ac9ve ingredient in aspirin is salicylic acid.
Predic*on:
It would be possible to achieve a low to moderate yield (around 15-55%) of the produc9on of aspirin.
As we must assess the purity of aspirin, we have produced in the lab. I would predict the mel9ng
point temperature to be 63°. Achieving a 100% percentage yield in a school laboratory would be
almost impossible due to mul9ple factors such as incomplete reac9ons or loss of product during the
prac9cal.
Variables and fair tes*ng:
To enable a fair test the synthe9sa9on of aspirin, the prac9cal would have to be completed with;
approximately 0.23g of salicylic acid, 25 drops of ethanoic anhydride, one drop of 85% phosphoric
acid and 0.7cm3 ethanol. The prac9cal could be performed several 9mes to ensure no anomalies or
mistakes are found within the prac9cal as that would affect the overall percentage yield.
The variable that can be changed would be the number of drops of 85% phosphoric acid added as a
catalyst for the reac9on, adding more 85% phosphoric acid could decrease the percentage yield, or
adding less 85% phosphoric acid could increase the percentage yield but this would be 9me
consuming in a laboratory seYng.
The variables that would stay the same would be the number of ethanoic anhydride added, the
temperature of the water bath and the set temperature when using the “Mel-temp” mel9ng point
apparatus to determine the purity of aspirin.
Equipment and technique:
- Beaker - Conical flask - Scoopula
- Test tubes - Water bath - Watch glass
- Balance - Melt-temp apparatus
- Graduated cylinder - Wash bo`le
- Thermometer - Filter paper
Synthesis of aspirin:
Image 1
Some reac9ons require heat for the reac9on to begin, with the synthesis of
aspirin heat would be required for the ethanoic anhydride and phosphoric acid
to mix with the salicylic acid so that once it has been in the water bath for
enough 9me it should now be a clear liquid. Heat also increases the rate of the
reac9on, causing the product of the reac9on to form faster.
Determining the purity of aspirin:
C: Explore manufacturing techniques and tes9ng methods for an organic solid
Aim
The aim of this prac9cal was to be able to explore manufacturing techniques and tes9ng methods of
organic solids. We were assigned with the task with synthesising aspirin. Aspirin has medicinal
proper9es such as pain relief, fever reducer and is also a swelling reducing drug (NSAID). The most
ac9ve ingredient in aspirin is salicylic acid.
Predic*on:
It would be possible to achieve a low to moderate yield (around 15-55%) of the produc9on of aspirin.
As we must assess the purity of aspirin, we have produced in the lab. I would predict the mel9ng
point temperature to be 63°. Achieving a 100% percentage yield in a school laboratory would be
almost impossible due to mul9ple factors such as incomplete reac9ons or loss of product during the
prac9cal.
Variables and fair tes*ng:
To enable a fair test the synthe9sa9on of aspirin, the prac9cal would have to be completed with;
approximately 0.23g of salicylic acid, 25 drops of ethanoic anhydride, one drop of 85% phosphoric
acid and 0.7cm3 ethanol. The prac9cal could be performed several 9mes to ensure no anomalies or
mistakes are found within the prac9cal as that would affect the overall percentage yield.
The variable that can be changed would be the number of drops of 85% phosphoric acid added as a
catalyst for the reac9on, adding more 85% phosphoric acid could decrease the percentage yield, or
adding less 85% phosphoric acid could increase the percentage yield but this would be 9me
consuming in a laboratory seYng.
The variables that would stay the same would be the number of ethanoic anhydride added, the
temperature of the water bath and the set temperature when using the “Mel-temp” mel9ng point
apparatus to determine the purity of aspirin.
Equipment and technique:
- Beaker - Conical flask - Scoopula
- Test tubes - Water bath - Watch glass
- Balance - Melt-temp apparatus
- Graduated cylinder - Wash bo`le
- Thermometer - Filter paper
Synthesis of aspirin:
Image 1
Some reac9ons require heat for the reac9on to begin, with the synthesis of
aspirin heat would be required for the ethanoic anhydride and phosphoric acid
to mix with the salicylic acid so that once it has been in the water bath for
enough 9me it should now be a clear liquid. Heat also increases the rate of the
reac9on, causing the product of the reac9on to form faster.
Determining the purity of aspirin:
