The analysis of aspirin
ANALYSIS OF ASPIRIN TABLETS
The aim of this investigation is to determine the percentage by mass of aspirin aspirin present in different commercial preparations and to find out, which the best value is, using a neutralization reaction followed by a direct titration with NaOH.
Chemicals Used:
100 ml of distilled water in a wash bottle
50 ml of 0.100 M NaOH
40 mL of 96% ethanol phenolphthalein as an indicator (3 drops per titration)
325 mg non buffered aspirin tablets
Materials Used:
One spatula
Two Erlenmeyer flasks, 250 ml
One weighing scale (with uncertainly +-0.005g)
1000 ml graduated cylinder
Buret
One metal stand
Buret clamp
50 cm3 conical flask
Procedure:
The metal stand was assembled with the buret. The latter one was filled with 0.100 M NaOH to just above the 0.00 mark. There was no bubbles apparent in the burette.
One table of aspirin was grinded into a fine powder by using a mortar and pestle. A weighing boat was placed on the balance and tare. The powdered sample was carefully transfered to the weighing boat and the mass was determined. The result was recorded on the data table.
The powdered sample was placed into a.Then a 10.0 mL portion of ethyl alcohol was added and swirled. At first it was difficult to dissolve the white powder, even after some period of swirling little amount of solid may be seen at the bottom of the flask. The solutions seemed to be not as transparent as expected.
Three drops of the phenolphthalein indicator was put into the 50 cm3 conical flask and the solution was swirling constantly.
.
5. The burette is filled with 0.100M NaOH. Make sure there are no bubbles apparent in the burette. Record the initial volume of the base and the initial volume of the aspirin on the data table.
Add 25.0mL of water to the flask.
The titration began after adding a first portion of NaOH in 1.0mL increments while constantly swirling, until the solution turns a very light pink. (The equivalence point is approximately
The aim of this investigation is to determine the percentage by mass of aspirin aspirin present in different commercial preparations and to find out, which the best value is, using a neutralization reaction followed by a direct titration with NaOH.
Chemicals Used:
100 ml of distilled water in a wash bottle
50 ml of 0.100 M NaOH
40 mL of 96% ethanol phenolphthalein as an indicator (3 drops per titration)
325 mg non buffered aspirin tablets
Materials Used:
One spatula
Two Erlenmeyer flasks, 250 ml
One weighing scale (with uncertainly +-0.005g)
1000 ml graduated cylinder
Buret
One metal stand
Buret clamp
50 cm3 conical flask
Procedure:
The metal stand was assembled with the buret. The latter one was filled with 0.100 M NaOH to just above the 0.00 mark. There was no bubbles apparent in the burette.
One table of aspirin was grinded into a fine powder by using a mortar and pestle. A weighing boat was placed on the balance and tare. The powdered sample was carefully transfered to the weighing boat and the mass was determined. The result was recorded on the data table.
The powdered sample was placed into a.Then a 10.0 mL portion of ethyl alcohol was added and swirled. At first it was difficult to dissolve the white powder, even after some period of swirling little amount of solid may be seen at the bottom of the flask. The solutions seemed to be not as transparent as expected.
Three drops of the phenolphthalein indicator was put into the 50 cm3 conical flask and the solution was swirling constantly.
.
5. The burette is filled with 0.100M NaOH. Make sure there are no bubbles apparent in the burette. Record the initial volume of the base and the initial volume of the aspirin on the data table.
Add 25.0mL of water to the flask.
The titration began after adding a first portion of NaOH in 1.0mL increments while constantly swirling, until the solution turns a very light pink. (The equivalence point is approximately