Analysis/Conclusion:

The purpose of this lab was to determine the molecular weight of a compound by measuring the freezing point depression.During this lab, lauric acid was reacted with an unknown solute. With the addition of lauric acid, the freezing point dropped om average from 44.0 °C to 40.35 °C . The first trial produceda formula weight of 87.496 g/mol, and the second trial produced a formula weight of 109.017 g/mol. Neither trial produced a formula weight similar to the compounds listed in Table 1. The failure to confirm the identity of the unknown solute was justified by the high percent error or 28.52%. The identity of the unknown was only confirmed as benzoic acid, when the instructor revealed the name of the compound at the end of the lab. Therefore, the results of this lab were fairly inaccurate, for the identity of the compound would have been determined by simply using the calculated formula weights.

As in any lab, the possibility for error is inevitable. For example, the stopper needed to be inserted quickly and tightly as the lauric acid was added in order to capture the gas, and accurately graph the freezing point. If the stopper was not inserted quickly and tightly enough, some of the gas produced may have been released into the air, falsifying the data. Additionally, if the probes were not inserted properly, and were thus not air tight, gas also would have been able to escape during the reaction. In future labs, I would emphasize the importance of properly inserting probes, and quickly and tightly inserting the stopper into the flask, in order to preserve data and ensure accurate results. I would also increase the number of trials for this lab, in order to achieve more plentiful and accurate data.