VARYING THE AMOUNT OF SULFURIC ACID IN

THE SYNTHESIS OF ASPIRINBy: Jess Withey and Dr. David Oostendorp, Ph.D.

1. Introduction Aspirin is a true wonder drug. Used mostly as a pain reducer and

fever fighter. Reduces the incidence of heart

disease, strokes, and certain cancers. Improves brain function in people

who have suffered small strokes, prevents cataracts, and reduces the occurrences of gallstones.

2. Objective Use infrared (IR) spectroscopy to

observe the effect of acid catalyst (sulfuric acid) in the synthesis of aspirinIRs are analytical techniques used to

identify functional groups in a molecule based on their absorption of electromagnetic radiation in the infrared region.

Calculate and compare percent yields

3. Reaction

4. Chemical List 30mL distilled water 15.0mmol salicyclic acid 5.0mL acetic anhydride Concentrated sulfuric acid (0.0-0.4mL) Ice

5. Methods:REACTION PROCESS: Mix 15.0 mmol (about 2.0g) acetic anhydride

and 5.0 mL salicyclic acid in Erlenmeyer flask. Concentrated sulfuric acid was added with

stirring. Mixture was heated for 6 minutes at 45-50

degrees Celcius. Mixture was set out to cool and crystallization

occurred. 30.0mL of water was added; clumps were broke

apart using a stirring rod. Mixture was placed in ice for a couple minutes

to become solid-like.

SEPARATION PROCESS: Mixture was separated using vacuum

filtration Mixture was washed with cold water Product was saved and dried

6. Results Experiment was performed 15

times. Three total trials for each

amount of H2SO4. The amount of H2SO4 added

ranged from 0 to 0.4mL. Products were similar in color,

amounts and texture varied.

Figure 1:Below shows the percent yields in comparison to the amount of sulfuric acid that was added to the reaction.

0

10

20

30

40

50

60

70

80

90

62.4

71.576.4

72.3

79.6

Amount of H2SO4 (mL)

Percent Yield

0 0.1 0.2 0.3 0.4

Crystallization Process 0.0mL-sugar, water mixture whole time 0.1mL-clear right away, 5 minutes 0.2mL-6 minutes 0.3mL-during reaction, 3 minutes 0.4mL-clear right away, 5 minutes

Figure 2:Below is the infrared spectroscopy of Aspirin as a result of the experiment for 0.1mL.

Figure 3: Below is the actual infrared spectroscopy of Aspirin.

Figure 4: Below is the infrared spectroscopy of Aspirin as a result of the experiment for 0.2mL (actual experiment).

7. Conclusion Results indicate that there is a

general trend that the percent yield increases with the addition of sulfuric acid.

Time varied to crystallize in reaction process.

The experiment’s infrared spectroscopy is verified to be Aspirin.

8. References Oostendorp, Dr. David. The Prentice

Hall Custom Laboratory Program for Chemistry; Pearson Learning Solutions: Boston, MA, 2010; pp 173-180.

Smith, Janice Gorzynski. Organic Chemistry, 3rd ed.; McGraw-Hill: New York, 2008; pp 476-477.