The two solvents in the unknown were correctly identified as acetone and toluene. The solvent with the lower boiling point was predicted to be acetone, as its boiling point was observed to be around 59 C, which was closest to the 56.5 C, the ideal boiling point of acetone. This result, however, had the possibility of being incorrect, since the boiling point of methanol, 64.7 C, was relatively close enough to the observed 59 C that methanol could have been incorrectly identified due to experimental errors such as turning the hot plate up too high. A similar situation could have occurred with toluene, the higher boiling point solvent, but this was less likely since there were no possible solvents that had a boiling point that close to toluene. The chromatogram confirmed the identity of the lower boiling point solvent as acetone, and the higher boiling point solvent as toluene.
In this experiment, 293 mg of aldehyde was weighted for method 1 instead of 250 mg and. Although .7906 mg of phosphonium salt was added, this probably was not enough to complete the reaction. The only significant change throughout method was 1 was that the yellowish mixture became slightly lighter. However, it was found that after vacuum filtration, there was some white and yellow
Rf is equal to the distance traveled by the substance divided by the distance traveled by the solvent. Since the solvent used in the developing chamber was hexanes—a non-polar molecule— the more nonpolar the substance was, the stronger it would stick to the plate. This means that the more polar a pigment was, the higher it climbed on the TLC plate and would therefore have a larger Rf. There are 3 major classes of pigments present in spinach: carotenes, xanthophylls, and chlorophylls. Since the solvent is nonpolar, we would expect carotene to have the lowest Rf, then xanthophylls, and chlorophylls would have the highest.
The other additives that showed great decrease in aging are Solprene 1205 and Calprene 6120. Solprene 1205 seemed to be working well with the 64-22 binder and Calprene 6120 showed high reduction in aging with 67-22 binder. Frequency sweep tests were performed on the binders modified with antioxidant additives to learn about the impact of these additives on linear viscoelastic properties of the binders. The testing was done on both unaged and PAV aged samples. The frequency sweep test was done at 7 temperatures: 10,20,30, 40, 50, 60 and 70ºC and 10 frequencies at each temperature.
The nucleophile in this particular SN2 reaction was iodine and, as stated before, the leaving groups for 1-bromobutane and 1-chlorobutane are bromine and chlorine respectively. Bromine is a better leaving group than chlorine however, so the fact that 1-bromobutane reacted before 1-chlorobutane corresponds directly with what would be expected. As stated before, primary is more reactive than secondary and even more reactive that tertiary. This explains why no reaction/change was seen for 2-chlorobutane, 2-bromobutane, and tert-butyl-chloride. 2-bromobutane would have been expected to react next, due to bromine being a better leaving group than chlorine, then 2-chlorobutane.
Retrieved from EBSCO with Full Text Database. This clinical review was written by Dr. Todescan assistant professor of dental diagnostic and surgical sciences, Professor Lavigne faculty of school of dental hygiene, and Dr. Kelekis-Cholakis director of graduate periodontics program, University of Manitoba. The article provides guidance to clinicians on how to properly care for patients with dental implants. Dental implants are being used more frequently to replace missing dentition and require just as
If you have a sample of the actual material, then the best way to compare melting points is to do a melting point test by mixing the known pure with the uncertain product. The melting points ranged from 46°C-51°C. The melting point illustrates that the sample of trimyristin obtained was pure. The value was lower than what the trimyristin was stated to the weight given that impurities lower the MP. It takes less energy to disrupt crystal lattice when impurities are present given that it makes the melting point become lower and broader.
The silver colloidal particles obtain a negative charge because of to the adsorbed citrate ions; The absorption peak was observed at about 420nm which is the typical characteristic absorption peak for Ag nanoparticles. UV absorption peak of chitosan-Ag nanoparticles was observed by other researchers in the range 410–450
In the control, beta-amylase was present unlike the experiment, which resulted in less molecules lingering. Discussion: 1. a. My results matched my prediction regarding alcohol percentage by weight. I predicted that the control would have a higher alcohol content than the experimental since beta and alpha amylase are working together. Since only Alpha-Amylase worked in the experimental, there was probably bigger carbohydrates present in the flask, therefore, there was a lower alcohol percentage since yeast can’t digest bigger sugars.
only 13 of these have experienced clinical trials. The most promising are carboplatin and oxaliplatin. Second and third analogues of cisplatin were designed in order to decrease its toxicity towards healthy cells whilst retaining its anti-proliferative activity (Figure 2). They have similar features to cisplatin, namely its platinum ion at the centre. The second generation analogue is carboplatin this is much less reactive than cisplatin and shows less toxicity.