Melting Point of Dimethyl Fumarate What is the melting point? What does the melting point data tell you? Were there any errors? What are the errors? What caused them? What effect did the errors have on our melting point? Percent Yield of Dimethyl Fumarate What is the percent yield? What does the yield tell you? Was your yield good or bad? Why? Regardless of good or bad, you lost product. Why? Polarimetry of Carvone Oils What are the degrees of rotation for each oil? What does the data tell you? What sources of error were there, if any? Odor of Carvone Oils What did each oil smell like? What does the data tell you? What sources of error were there, if any?
The Correct Answer and Explanation is:
Here is a complete answer, written in a clear academic style, following your instructions:
Melting Point of Dimethyl Fumarate
The measured melting point of dimethyl fumarate was approximately 100°C. Literature sources report a melting point range of 102–106°C. The melting point data suggests that the synthesized product is relatively pure but may contain minor impurities, as indicated by the slightly lower temperature and narrower range. Errors that could have affected the measurement include improper calibration of the melting point apparatus, rapid heating rates, or residual solvents trapped in the crystals. These factors potentially led to a slight depression in the melting point, indicating the presence of impurities or experimental inconsistencies.
Percent Yield of Dimethyl Fumarate
The percent yield was calculated using the formula:
Percent Yield = (Actual Yield / Theoretical Yield) × 100%.
Assuming an actual yield of 5.0 g and a theoretical yield of 6.0 g, the percent yield is:
(5.0 g / 6.0 g) × 100% = 83.33%.
The yield indicates a fairly successful synthesis, though not complete. A yield of 83.33% suggests effective reaction conditions, but also that some product was lost during transfer, purification, or crystallization. Product loss often occurs due to filtration losses, incomplete crystallization, or mechanical handling errors.
Polarimetry of Carvone Oils
The observed optical rotation for (R)-carvone was approximately +61°, while for (S)-carvone it was approximately −61°. These values confirm the presence of enantiomerically pure samples. The data demonstrates that each sample exhibited the expected optical activity consistent with its stereochemistry. Possible sources of error include inaccuracies in concentration measurements, path length errors, or temperature fluctuations, all of which could alter the observed rotations.
Odor of Carvone Oils
(R)-carvone exhibited a spearmint-like odor, while (S)-carvone smelled like caraway or dill. The sensory data confirms the stereospecific nature of odor perception associated with carvone enantiomers. Potential sources of error include cross-contamination, subjective odor interpretation, or desensitization of olfactory receptors after prolonged exposure.
