Abstract: . . .  on its side, and rotate it to spread the liquid over the inside surface of the flask. Finally, release the vacuum line, and cool the flask in ice. II. Characterizing the product Read Sorrell pp. 691 708 and Mohrig pp. 610-627 on proton NMR. A. Melting point Determine the melting point of the hydrogenated olive oil by placing it in a small disposable test tube in water at various temperatures. The approach is necessary because the melting point is low, and because it is impossible to get the material in a capillary tube. B. Spectroscopic analysis Infrared and elementary proton NMR will be used to explain the observed melting point. The details will be made more clear in a handout. For now, try to digest the rudiments of NMR.  . . .
. . .  percent glyceryl trioleate is present, melting can easily be seen to begin by about 5. Similarly, a mixture of C 18 C 18 C 18 , C 18 C 18 C 18 , and C 18 C 18 C 18 should begin to melt at about 5 and be complete by about 25 even if a few percent stearate (C18 saturated) is present in the mixture. Rancidity Polyunsaturated fatty acids such as linoleic and linolenic oxidize easily in air. Thus, linseed oil, which contains a large percentage of linolenic acid, is an excellent vehicle for oil- based paint because oxidation cross-links the fatty acid molecules to form a strong film. However, what is good for paint evidently is not good for you. Just as excessively saturated fats are not part of a sound diet, neither are ones containing excessive amounts of polyunsaturated fatty acids (e.g. linoleic and linolenic). The CH2 interrupted multiple double bonds (called- homoconjugated) encourage oxidation, which breaks the hydrocarbon chains. The fragments, which usually terminate in an aldehyde group, are volatile and smelly. The fat is call rancid. Partial hydrogenation, of plant oils reduces rancidity because it reduces the number of homoconjugated polyunsaturated fatty acids. Isolated double bonds, as in oleic acid, do not oxidize under ordinary conditions. . . .
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