This distillation is performed in one step. Furthermore, fractional distillation consists of a fractionating column in addition to the other apparatus. Fractional distillation is used when two compounds' boiling point differs by less than 40 C so that a better separation occurs. Figure 5 is a graph of
Fractional Distillation and Gas Chromatography (Investigative) Kevin Dural The University of Texas at Austin Fractional Distillation and Gas Chromatography (Investigative) Data and Results All data and results are attached. Included are carbon copies of written data and printed gas chromatography data. Discussion The purpose of this experiment was to identify two unknowns and their ratios in a given mixture. The identities of the unknowns were two of either acetone, methanol, hexane, cyclohexane, heptane, toluene, or ethyl benzene. Distillation Distillation is used to remove impurities from a mixture – one component of which must be a liquid.
In this experiment we have 6% salt solution, 12% salt solution, 18% salt solution and 24% salt solution. We are going to weigh out the mass of the dry glassware, which will be a volumetric flask, and then the mass of the glassware with the water in it. After we measure the glassware with the water in it
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. At this point I found that if the hot plate was at 147˚C the solution boiled more vigorously, meaning that my ketone hade a boiling point of 147˚C, which was close to the known boiling point value for 3-heptanone, 146˚C. The hot plate was turned down after this was noticed. After the solution was heat, approximately for five minutes, the mass was found for the bottom layer, which was 2.27g, and the percent yield was calculated. The percent yield was determined by taking the mass of the final ketone and dividing it by the original mass of the alcohol.
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.
The substitution reaction was successful but not fully effective. 19. If the data was inconclusive, then comparing various compounds and the unknown based on physical characteristics would be the first step, titrations would also be a good method. 20. To get a better yield, redoing the experiment would require careful attention in the recrystallization steps: amount of solvent used, how hot solvent is, if the mixture cools to room temperature before placing it in an ice
This was proved by utilizing the IR spectrum to verify the C=O was not in the final product as it lacked the 1640 cm-1 peak. The melting point of 113-115 degrees C proved that the final product obtained was the E-Stilbene. The TLC plate proved that the E and the Z product was produced, show cased by the double intensity of the DCM spot to the final product’s spot, both which had an Rf of 0.92. The double intensity proved that both products were produced, but through heating and filtering, the Z-Stilbene was
As well as the ending line, where the solvent stopped. The higher the compounds go up the more polar the substance is. (1) On the TLC that was done in the practical 1 two lines had roughly the same distance of 2.55-2.6cm. The reaction material was higher of about 2.9cm and the final product was lower (1.9cm). This means that the reaction materials had a higher polarity than the other 3.
Once the solvent was used straight from its original bottle, the pigments began to separate. In addition, the solvent was not always at equal levels as it was difficult to precisely measure with the pipet. The measuring tool used for this experiment was not the most precise instrument that could have been used. This may have led to some miscalculations, but as seen before, they were not
Introduction The purpose of this experiment was to purify acetanilide that was contaminated with relatively small amounts of impurities using recrystallization. The success of recrystallization was dependent on a suitable solvent being chosen and proper recrystallization technique being carried out. The solvent chosen had to have a different polarity than that of the molecule of interest. The technique used was dependent on the solubility of the solvent at higher temperature and the solubility of the impurities at all temperatures. To analyze the acetanilide product of the reaction, 1H NMR and IR were used.