On the other hand, the crude product versus the known product is similar which makes them identical. This also interprets to the products and reactants were pure. Then, the 2nd TLC plate was based on the interval of the student’s product while it was heating.. The TLC plate shows purity as well as the concentration gradually increasing. This is what prevents the spots from becoming darker during the 15 minute reflux process.
The 1:1 hexane to ethyl acetate solvent resulted in the best separation because it not only showed extra spots that the other solvent mixtures did not have, but also the 4 spots were relatively dispersed with Rf values at 0.77, 0.56, 0.27, and 0.10 (Figure 2). Missing spots were also noted on the hexane only TLC plate. The orange eluent was ultimately chosen as our major product because it had significantly different TLC results than the 3 yellow eluents with the same Rf of 0.23 (Figure 3). The percent yield for this purification method was 248% and the extrapolated percent purified yield was around 135 %, which are both erroneously high. These high percent yield may be due to extra water weight or not fully evaporated
In our experiment, we were able to synthesize isopentyl acetate by heating a reaction mixture of isopentyl alcohol with excess acetic acid. We were then able to purify the isopentyl alcohol by using the methods of extraction, drying, and distillation. Our synthesis and purification of isopentyl acetate was fairly successful in allowing us to obtain and analyze banana oil. Questions 1. In addition to using excess acetic acid to form the ester, the reaction can also be influenced by removing water from the reaction mixture.
Hence, a calcium chloride and cotton were filled inside a drying tube. The condenser was wrapped with parafilm and a paper towel to avoid moistures from entering. The reagent will act as nucleophilic addition to acetone and work up with hydrochloride acid to synthesize 2-methylhexanol. Throughout this process, the solution turns dark grey and develop white precipitates. This step indicate that Grignard reagent was generated, and the extra white precipitates were magnesium.
Thus, a higher percent yield was calculated for acetaminophen. Although, a second filtration was performed; however, a very low concentration of acetaminophen was recovered as a result of human errors, and the transfer of solution/solid contributed to product loss. However, the mass use to calculate percent yield was the first mass recorded because it may be more consistent than the mass measured after the second filtration. However, for further experiments, the percent yield must be calculated with the corresponding mass of product (actual yield) even though there is loss of product, the actual yield is the final concentration of the recovered product in the experiment. Thus, the results may be more conclusive if the actual percent yield was used.
The change in solvents throughout the elution process would allow for an effective and efficient separation of the compounds β-carotene and chlorophyll in the crude extract of green leaves. The polar silica gel in the column is the stationary phase and acts as an adsorbent, depending on the affinity of the component towards the stationary phase. In general, the more polar component would have a stronger interaction with the stationary phase, and the less polar component would be eluted out first. From the observations of the column chromatography, yellow S2 collected is β-carotene, indicating that
1,3-butadiene is formed from 3-sulfolene by thermal decomposition. It is important to work with very concentrated solutions of two different reagents because they help create the bonds in the six-membered ring. The reagent that was taken in excess was xylene. Xylene, a non-polar solvent, can be used for this reaction because it will not react with the solvents. Xylene should be dried because it will be removed from the product.
This means that the reaction acted quicker and would increase the probability of the sample being pure, this would mean that you didn’t have to wait very long and the material changes that have taken place whilst the reaction was taken place would be easier to define and make a note of the start and end point. The precipitation reaction forms aspirin crystals which involves joining ions in solutions to form a precipitate. Another technique that we used was filtration. The equipment we used was a Buckner which uses gravity and a vacuum and this gets rid of the moisture in the sample and creates a dry sample. Another technique would be dissolving and reacting which involves the crystals to be made and for the chemicals to react to make the
Lactic acid is produced by two methods i.e, chemical method and fermentation method. Chemical method utilizes petrochemical resources followed by addition of HCN and specific catalyst to produce lactic acid . While fermentation methods utilizes renewable resources such as carbohydrate in a fermented broth to obtain lactic acid . Optical purity of lactic acid is very important and hense is major addressed problem in production of PLA. Chemical method produces racemic mixture of both D(-) and L(+) lactic acid while fermentation methods produces only one optically pure form of D(-) or L(+) lactic acid
Solutions such as isotonic saline or Ringer Lactate are least harmful when absorbed into the circulation. Although sterile water has many qualities of an ideal irrigating fluid, its disadvantages are extreme hypotonicity, shock, and kidney failure. Sterile water is an inexpensive alternative to isotonic saline for irrigation during PNL. Although we did not find any difference between the two irrigation fluids with regard to the safety for smaller calculi, its safety has to be confirmed with larger studies, especially for large