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.
During the process a mixture is separated into several parts called fractions. Mixtures contain different substance with different boiling points, the differences in boiling points is the main reason fractional distillation is effective. The temperature at which a phase change occurs from liquid to vapor is the boiling point. Fractional distillation Column Fractional distillation column is a fractionating column used for separating a mixture into its various
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.
The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst.
This was proven partially correct, because the algae showed signs of greenness for two weeks after we added the pollutant, but began to die off in the third week of our experiment. Furthermore, the amount of algae seemed to decrease, which was very surprising. As a matter of fact, this also happened to several other containers of algae, such as Positive Control and Carbonated Beverage. The amount of algae seemed to decrease, which was strange because we never removed the algae from its container. The sixth hypothesis predicted that if a chunk of petroleum jelly was added to algae, the algae would grow slower than the positive control.
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. b. My results also matched my prediction regarding mean reducing carbohydrate levels during the mashing process between the control and the experimental. My prediction stated that there would be less reducing carbohydrate ends in the experimental, which was proven in the data table. c. My results also matched my prediction regarding the amount of carbohydrates left after fermentation in the flasks.
Excessively addition of coagulants can be avoided by using EC, due to the generation of the coagulants by electro oxidation of a sacrificial anode. EC has easy operation and simple equipment. The most common electrode materials used for EC are aluminum and iron. They are readily available, economical, very effective. When aluminum is used as electrode material, the reactions
For this reason, three different molar masses were calculated. This ensures that calculations were accurate for each trial. The first trial saw a large percent error of 19%. This error was caused because a few bubbles of butane gas escaped the graduated cylinder, decreasing the volume of butane gas in the cylinder. The percent error associated with the second and third trial was much better than that of the first trial.
However, If a mistake was made by adding too much water or too much KI, the error would be carried on and therefore will have influenced the overall results greatly. There are not a lot of improvements to this, but one way is to dilute the concentrations 1 by 1 instead of going through a serial dilution although it takes a vast amount of time. The 5 second wait before adding KI: Since there was a 5 second wait before adding the KI into the mixture of different solutions, and also that this was added manually, the prediction of 5 seconds may have varied and therefore could have minor effects on the absorbance change. Instead of allowing 5 seconds to pass before adding the solution of KI into the mixture, all of them could be added at once and data collection can start
To have gotten a 0% error between the experimental and actual value for CH3COOH, the pH would have been measured at about 4.75, which is slightly more acidic than 4.80. The percent error was calculated to determine how accurate the Ka of acetic acid was: Since the calculations yielded a 20% error, this shows that experimental error occurred during the experiment. Factors that could have affected the results included improper reading of the meniscus for volume of NaOH, not allowing the NaOH to fully drip into the buret after removing the funnel, adding too much acetic acid after the indicator flashed pink to get an inaccurate equivalence point, and not allowing the solution in the beaker to mix thoroughly to get an accurate reading from the pH