Simple Distillation Lab Report

TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.

This aqueous solution was then heated until all the dichloromethane evaporated off. An error could have occurred at this point in the experiment if the hot plate was too hot. If the hot plate was set above the boiling point of the ketone, the ketone could have evaporated of along with the dichloromethane. This would result in a lower percent yield of the ketone. To prevent this from happening, the hot plate should not exceed 130˚C, so no matter what ketone was isolated, it would not evaporated off.

In the lab, “Properties of Hydrates,” the purpose was to compare the properties of several well observable hydrates and to determine if dehydration is a reversible or irreversible change. The lab consisted of attaining a pea-size sample of each compound, burning it over a bunsen burner, and comparing the starting mass and the mass lost after the combustion. These results are important to be able to identify a variety of different chemicals that contain water molecules as part of their crystalline structure. Some can be removed by heating (resulting in evaporation) and some remain mostly unchanged. In this lab the answer will be found.

In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone. In this test, primary halides precipitate the fastest while secondary halides need to be heated in order for a reaction to occur. Comparison of the rates of precipitation of the obtained product to standard 1° and 2° bromide solutions will show whether the product is a primary or secondary

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

As the experiment went on, and as the blue copper chloride was turning clear, the reaction of the aluminum foil was slowing. The lighter the copper chloride got, the slower the red stuff was being produced. The purpose of this experiment was to determine what that red stuff was, aluminum or copper. The red stuff that was produced eventually dried out overnight and when I came back next class, it was completely dry. When it is dry, it is really fragile, it breaks to the touch and it stains anything it breaks apart on.

One error that could have affected the percent yield is not filtering out all of the liquid from the filter paper in the funnel before setting it off to dry. This would have increased the final mass of the solid, not making it accurate. To stop this from happening again, the liquid could be drained more thoroughly until it fully stops dripping into the Erlenmeyer flask. Another error that could have affected the percent yield is the amount of trials performed. This would have made the results less accurate and made any errors change the final results even more.

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.

Concepts learned include molar ratio calculation, and ester constituents (carboxylate acid and alcohol). In addition, the use of a cold finger condenser and its purpose in ester reactions was discovered. The effects of drierite on reactions and its ability to absorb water was also studied. Concepts of stoichiometry were reviewed from previous classes, and integrated into this lab experiment as well. Citations: Thorne, E. J.

Substrate concentration basically means the amount used for the substrate. The substrate in our experiment was 0.1% hydrogen peroxide. The 0.1% is the concentration amount. Just like temperature and pH, substrate concentration can speed the reaction only up to a certain limit. When we mixed pH 3 enzyme tube with substrate tube, we used 0.3 mL of hydrogen peroxide, but if we were to increase the amount, then the experiment would have been faster.