Laboratory Report

I. Title:
We will use titration to determine the purity of synthesized aspirin. In doing so, we will measure the volume of the aspirin accurately. Then, we will use NaOH to titrate the aspirin solution. The analysis of this titration data will allow use to calculate the percentage of acid in the original solution. We will then compare these values to those expected is the sample was made from pure acetylsalicylic acid. The difference from this will come from impurities.

II. Authors:
Katie Warren, Annie Haman & Jacob Brotherton

III. Abstract:
The mass of acetylsalicylic acid was determined using a analytical balance. Sodium hydroxide (NaOH) was added to the “white powder” to titrate to produce a persistent, pale pin endpoint. The percentage purity of aspirin was found to be 74.88%.

IV. Pre-lab assignment:
OMIT

V. Procedure:
Refer to the lab handout for procedure

VI. Chemical Reactions:
Aspirin Synthesis: NaOH (aq) + KHC8H4O4 (aq) NaKC8H4O4 (aq) + H2O (I)
Aspirin Titration: HA (aq) + NaOH (aq) H2O (I) + NaA (aq)

VII. Experimental/Calculated Data: Table 1: Mass of Aspirin | Trial 1 | Mass Watch Glass + White Powder (g) | 38.2625 | Mass of Empty Watch Glass (g) | 37.72 | Mass of White Powder | .5425 |

VIII. Calculations:

IX. Results and Discussion:

X. Conclusions:
We have experimentally determined and achieved the percent purity of the aspirin we had previously made. The volume of the solvent that dissolved the aspirin was not very accurate, however, the volume of NaOH used in the titration was very accurate. Some major sources of error in the experiment include: contamination of the aspirin, any math errors, an instrument error, and putting too much or not enough indicator in the solution.

XI. References:
Laboratory handout

XII. Appendix: