TASK 3
EXTRACTION OF PARACETAMOL
In order to extract paracetamol from a tablet, we warmed 2 paracetamol tablets
with 20 cm3 propanone in a conical flask by placing the flask in warm water. After
the tablets broke up into smaller particles, we filtered the undissolved material.
Then we allowed the propanone to evaporate on a warm water bath in a fume bath.
After a while we got a white solid which was crude paracetamol. We reserved a
small amount of the white solid for testing the melting point later. The material we
got was then later recrystallized from hot water by heating the solid in about 10 cm3
of water until it dissolved, then we filtered any insoluble material through a very
small piece of cotton wool in a warm glass funnel. We then cooled the filtrate and
filtered off the crystals that form (the recrystallization process is important because
it influences purity as paracetamol is not soluble in cold water but very soluble in
hot water which makes it easy to remove soluble impurities). We let the pure
paracetamol dry and warmed it in an oven.
The melting point of our crude sample we got was measured and compared to that
of and the literate melting point of pure paracetamol as shown in Table 1.
OBSERVATION
After mixing the 2 paracetamol tablets with propanone, a white solid precipitate was
formed and then filtered into a conical flask. The white solid was crude paracetamol.
We then allowed the propanone to evaporate by placing the conical flask in a warm
water bath. The product was then recrystallized by heating and filtered off through a
small piece of cotton wool in a warm glass funnel. The final product we ended up
with was white.
TABLE OF RESULTS
Substance Melting point / ºC
Crude paracetamol 165
Pure paracetamol 169
Crude paracetamol: 3.422 g
Recrystallized paracetamol: 2.815 g
% purity = mass of useful products/ total mass of sample x 100
EXTRACTION OF PARACETAMOL
In order to extract paracetamol from a tablet, we warmed 2 paracetamol tablets
with 20 cm3 propanone in a conical flask by placing the flask in warm water. After
the tablets broke up into smaller particles, we filtered the undissolved material.
Then we allowed the propanone to evaporate on a warm water bath in a fume bath.
After a while we got a white solid which was crude paracetamol. We reserved a
small amount of the white solid for testing the melting point later. The material we
got was then later recrystallized from hot water by heating the solid in about 10 cm3
of water until it dissolved, then we filtered any insoluble material through a very
small piece of cotton wool in a warm glass funnel. We then cooled the filtrate and
filtered off the crystals that form (the recrystallization process is important because
it influences purity as paracetamol is not soluble in cold water but very soluble in
hot water which makes it easy to remove soluble impurities). We let the pure
paracetamol dry and warmed it in an oven.
The melting point of our crude sample we got was measured and compared to that
of and the literate melting point of pure paracetamol as shown in Table 1.
OBSERVATION
After mixing the 2 paracetamol tablets with propanone, a white solid precipitate was
formed and then filtered into a conical flask. The white solid was crude paracetamol.
We then allowed the propanone to evaporate by placing the conical flask in a warm
water bath. The product was then recrystallized by heating and filtered off through a
small piece of cotton wool in a warm glass funnel. The final product we ended up
with was white.
TABLE OF RESULTS
Substance Melting point / ºC
Crude paracetamol 165
Pure paracetamol 169
Crude paracetamol: 3.422 g
Recrystallized paracetamol: 2.815 g
% purity = mass of useful products/ total mass of sample x 100
