Vernier Software and Technology
Vernier Software & Technology

The Synthesis and Analysis of Aspirin

Figure from experiment 22 from Advanced Chemistry with Vernier


Aspirin, the ubiquitous pain reliever, goes by the chemical name acetylsalicylic acid. One of the compounds used in the synthesis of aspirin is salicylic acid, which is itself a pain reliever that was known to many ancient cultures, including the Native Americans who extracted it from willow tree bark. Salicylic acid is extremely bitter tasting, and frequent use can cause severe stomach irritation. The search for a milder form of this pain reliever led to the successful synthesis of acetylsalicylic acid by the German chemist Felix Hoffmann in 1893.

Your two primary objectives in this experiment will be to synthesize and analyze aspirin. There is more than one way to synthesize aspirin; in this experiment, you will react acetic anhydride with salicylic acid in the presence of phosphoric acid (which acts as a catalyst). The reaction equation is shown below.

{\left( {{\text{C}}{{\text{H}}_{\text{3}}}{\text{CO}}} \right)_{\text{2}}}{\text{O }} + {\text{ HO}}{{\text{C}}_{\text{6}}}{{\text{H}}_{\text{4}}}{\text{COOH }} \to {\text{ C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{O}}_{\text{2}}}{{\text{C}}_{\text{6}}}{{\text{H}}_{\text{4}}}{\text{C}}{{\text{O}}_{\text{2}}}{\text{H }} + {\text{ C}}{{\text{H}}_{\text{3}}}{\text{COOH}} Acetic{\text{ }}anhydride{\text{ }} + {\text{ }}salicylic{\text{ }}acid \to acetylsalicylic{\text{ }}acid + acetic{\text{ }}acid

You will conduct two tests of your synthesis to verify that you did indeed make aspirin, and to determine its relative purity. First, you will measure the melting point of a sample of your product. Second, you will use a Colorimeter or Spectrometer to test the absorbance of your aspirin after it has been “prepped” with an iron solution to give it color.


In this experiment, you will

  • Synthesize a sample of acetylsalicylic acid (aspirin).
  • Calculate the percent yield of your synthesis.
  • Measure the melting temperature of your aspirin sample.
  • Conduct a colorimetric analysis of your aspirin sample.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Option 1

Option 2

Option 3

Option 4

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Standards Correlations

See all standards correlations for Advanced Chemistry with Vernier »

Advanced Chemistry with Vernier

See other experiments from the lab book.

1The Determination of a Chemical Formula
2The Determination of the Percent Water in a Compound
3The Molar Mass of a Volatile Liquid
4Using Freezing-Point Depression to Find Molecular Weight
5The Molar Volume of a Gas
6Standardizing a Solution of Sodium Hydroxide
7Acid-Base Titration
8An Oxidation-Reduction Titration: The Reaction of Fe2+ and Ce4+
9Determining the Mole Ratios in a Chemical Reaction
10The Determination of an Equilibrium Constant
11Investigating Indicators
12The Decomposition of Hydrogen Peroxide
13Determining the Enthalpy of a Chemical Reaction
14ASeparation and Qualitative Analysis of Cations
14BSeparation and Qualitative Analysis of Anions
15AThe Synthesis of Alum
15BThe Analysis of Alum
16Conductimetric Titration and Gravimetric Determination of a Precipitate
17Determining the Concentration of a Solution: Beer's Law
18Liquid Chromatography
20Electrochemistry: Voltaic Cells
22The Synthesis and Analysis of Aspirin
23Determining the Ksp of Calcium Hydroxide
24Determining Ka by the Half-Titration of a Weak Acid
25The Rate and Order of a Chemical Reaction
26The Enthalpy of Neutralization of Phosphoric Acid
27α, β, and γ
28Radiation Shielding
29The Base Hydrolysis of Ethyl Acetate
30Exploring the Properties of Gases
31Determining Avogadro's Number
32Potentiometric Titration of Hydrogen Peroxide
33Determining the Half-Life of an Isotope
34Vapor Pressure and Heat of Vaporization
35Rate Determination and Activation Energy

Experiment 22 from Advanced Chemistry with Vernier Lab Book

<i>Advanced Chemistry with Vernier</i> book cover

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