Preparation of Methyl Oleate
Essay by people • March 11, 2012 • Lab Report • 962 Words (4 Pages) • 3,600 Views
Conclusion:
The experimental objective of this lab was to reduce Methyl Oleate to Methyl Stearate via catalytic hydrogenation. This was achieved by adding Pd/C catalyst to the Methyl Oleate in the reaction flask, then adding 6M sulfuric acid to the zinc in the hydrogen generator. This was done at a slow rate over the course of an hour. The techniques used to analyze the obtained data were IR and H'NMR spectroscopy. The Bromine Test was also utilized in this experiment to test for the presence of unsaturated Carbon-Carbon double bonds. In using these techniques. it allowed for the determination of whether Methyl Oleate was still present, or if the reduction went to completion resulting in the formation of Methyl Stearate.
The H'NMR data was a bit mis leading at first as very few peaks were present. Methyl Stearate being such a long molecule, a more cluttered H'NMR spectrum was expected. Through careful speculation, it was depicted that the few number of peaks was indeed the correct spectra. The trends of the H'NMR observed seemed to show that the H's bonded to to Carbon that was bonded to an O were less shielded and gave a higher ppm reading. The first peak that appeared was a triplet at around 0.98 ppm. This doublet represented the methyl group bonded to the CH2 at one end of the molecule. (CH3-CH2) The next peak that was observed was at around 1.38ppm and was a singlet. This was the largest of all the peaks by a significant amount and accounted for approximately twenty-eight hydrogens. This peak represented all the equivalent CH2-CH2 bonds to one another in the long chain of Methyl Stearate. Due to the fact that they are all CH2-CH2 bonds, only a prominent singlet appears accounting for a majority of the H's. The next following signal was at around 1.7ppm. This peak was a bit harder to depict, but appeared to be a multiplet. This multiplet represented the CH2-CH3 bond at one end of the Methyl Stearate molecule and is represented by the letter B on the H'NMR data sheet. The next peak appeared at approximately 2.3ppm and has the splitting of a triplet. This peak is shown representing the CH2 that is bonded to the C=O near the other end of the Methyl Stearate molecule. The final peak that appeared was at 3.7ppm and had a singlet splitting. This peak represented the methyl group attached the O on the same end of the molecule as the previous peak and accounted for 3H's. There was also a minute set of peaks at around 5.65ppm and after depicting Methyl Oleate's true H'NMR on the SDBS database it was concluded that this set of peaks may indicate that there were traces of Methyl Oleate that remained in the product. In comparison with the SDBS database, the H'NMR spectra seemed to share similarities in signals thus concluding that Methyl Stearate was the prominent product obtained. The H'NMR data obtained showed correlation with that on
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