Fractions 1,2, and 3 were all separated by column/flash chromatography and their purities were measured with the TLC plate. One suggestion for future labs would be to use more accurate measuring tools. Post lab 1. So the solvent would not reflect the UV rays, therefore creating a dark spot on the luminescent TLC plate. This dark spot helps us measure how much the solvent moved on the TLC plate.
In part one of the lab we used a micro scale technique to derive an activity series for metals. With the use of this technique we measured the same amount of different metal nitrate solutions into each well. Then we placed a piece of metal in the other metal nitrate solutions. With the data we recorded we resulted our activity series for the metals. We resulted that lead, silver, and copper are the strongest oxidizing agents, and that magnesium and zinc are the weak oxidizing agents.
Melting Points Lab Abstract: One of the physical properties most relied upon for compound identification is a compound’s melting point. This experiment gives the student an opportunity to explore how compounds can be identified with this physical indicator. The experiment uses two compounds, tetracosane (C24H50) and 1-tetradecanol (C14H30O). The experiment confirms through melting points that the compound with more carbons and no branches (C24H50) has a higher melting point than 1-tetradecanol. Hypothesis: Using melting points can help determine the difference in total carbon atoms and branches between two or more compounds.
In the experiment, toluene was alkylated with 2-chloropropane to synthesize isomers of isopropyltoluene in 47% yield, weighing 2.66g. The final product had a purity of 91.8% while the appearance was a colourless clear liquid with a strong odour. The results suggest that although the product yield was low, the experimental design led to the production of isopropyltoluene in high purity. REFERENCES 1. Smith R, McKee J, Zanger M. The electrophilic bromination of toluene: Determination of the ortho, meta, and para ratios by quantitative FTIR spectrometry.
Also, the more stable the free radical that is left behind, the weaker its C-H bond strength will be. The difference between the bromine and chlorine product ratios can be partially explained by the Hammond postulate, which states that species with similar energy levels also have more similar structures and react more quickly and less selectively. In the experiment, five different hydrocarbons were tested to measure the rate of reaction with the addition of bromine. Two trials were done, one with the test tubes containing the hydrocarbons and added bromine sitting directly under a lamp, and another with the test tubes in a closed, dark space. Both trials contained a
Low density polyethylene (LDPE) – involves an older gas phase process (still used) with conditions: high pressure (1000-3000 times atmospheric), high temperature (300°C) and an initiator (an organic peroxide e.g. dibutyl peroxide, or oxygen). The resultant product has significant chain branching due to alkyl groups replacing hydrogen atoms on some carbon atoms. Consequently, the alkane chains cannot pack together in an orderly fashion, resulting in low densities and weak dispersion forces; therefore LDPE is soft, flexible and has a low melting point. The initiator isn’t strictly a catalyst as it is involved in the actual formation (one initiator molecule per ½ polymer molecule).
Out of all the acids that passed through, only one was found to be toxic. By using high performance liquid chromatography, a polar and nonpolar stationary phase that contained the toxin was mixed, and this isolated the toxin by itself. To ensure that that was the isolated toxin, they further broke it down to find its charge, size, and molecular shape. Mass spectrometry was then used to find the weight and formula of the toxin. By finding the formula, it had similar characteristics to an amino acid known as domoic acid.
The best electron microscopes can produce images almost __________times more detailed than light microscopes can. 11. Transmission Electron Microscopes (TEMs) shine a beam of electrons __________ a thin specimen. 12. Scanning Electron Microscopes (SEMs) scan a narrow beam of electrons back and forth across the __________ of a specimen.
The toxic waste can be managed by treating it well and burying it underground. Also new technology has made it possible to run Nuclear Power plants with thorium. To use thorium the Nuclear Power Plant needs to be driven on the Accelerator Driven System. This system may have a large price tag but it will pay itself back within fifty years or so. Thorium compared to Uranium creates less toxic waste and also unlike Plutonium (the by-product of uranium) the toxic waste created by Thorium will only takes 500 years to be declared safe.
Observations Data Table 1: Experiment Data | | Grams (g) | Percent of Mixture (%) | Initial Mixture | 6.5 | 100 | Iron Filings | 1.8 | 27.69 | Sand | 1.7 | 26.15 | Table Salt | 1.9 | 29.23 | Benzoic Acid | 0.8 | 12.31 | Combined Total | 6.2 | 95.38 | Questions A. How did your proposed procedures or flow charts at the beginning of this experiment compare to the actual procedures of this lab exercise? The flow chart I created listed each substance and the weight, it looked similar to the one on the disc but did not have a column for percentage B. Discuss potential advantages or disadvantages of your proposed procedure compared to the one actually used. The disadvantage of my flow chart would be that the weight would have been measured but the percentage would not give the accurate scientific measurements.