Boiling Points And Liquid Distillation

Solid impurities and liquid impurities having quite different boiling points are most easily removed by distillation, but even liquids having similar boiling points can be separated. For easy separations, a "simple distillation" apparatus (Figure 1) will be used for the first part, but for more accurate separations, a "fractional distillation" apparatus (Figure 2) is necessary. In this lab we will be using both apparatuses. Unfortunately, each time a distillation is run, material is lost. Some evaporates into the air and some is left behind, stuck to the apparatus. That is why fractional distillation is the best apparatus to use. It is important to keep a careful record of the temperature at the beginning and end of every fraction you collect. Stop the distillation by removing the heat just before all the liquid in the distilling flask is completely gone. Watching the rate of temperature increase is important, allowing the temperature to increase too quickly can cause impurity. The distillation curves for our simple and fractional distillation clearly demonstrate that fractional distillation separates the two compounds more

Method: Distillation is based on the fact that the matter can exist in three phases - - solid, liquid and gas. As the temperature of a pure substance is increased, it passes through these phases, making a transition at a specific temperature from solid to liquid (melting point--mp) and then at a higher temperature from liquid to gas (boiling point--bp). Distillation involves evaporating a liquid into a gas phase, then condensing the gas back into a liquid and collecting the liquid in a clean receiver. Substances that have a higher boiling point than the desired material will not distill at the

Objective: The main goal of this lab is to learn how separation of binary liquid mixtures is performed. Especially when the two liquids have boiling points varying by about 30° C. Hexane can be separated from toluene in this experiment because of the difference in their boiling points. Since toluene has a higher boiling point, it will left at the bottom while the hexane starts to boil out and collect in the Hickman still. GC measurements help us in determining how accurate our data is by making a graph of the amount of hexane and toluene in each fraction. Also this lab gives experience with semi-micro

In this experiment, distillations were done. This is a technique that utilizes the differing boiling points of two or more compounds in a mixture in order to separate the compounds from the mixture. The way fractional distillation works is that the initial mixture is boiled up to the point of the lower boiling point compound; this compound then evaporates. This compound is then

The next step in this lab is to rinse the Erlenmeyer flask with distilled water down the drain and then repeat the experiment, this time adding 10 ml of 0.10M KI and 10 ml of distilled water to the flask instead. The flask should again be swirling to allow the solution to succumb to the same temperature as the water bath and once it has reached the same temperature, 10 ml of 3% H2O2 must then be added and a stopper must be immediately placed on the flask and recording should then begin for experiment two. After recording the times, the Erlenmeyer flask must then be rinsed again with distilled water down the drain. After rinsing the flask, the last part of the lab can now be performed. Experiment three is performed the same way, but instead, 20 ml of 0.10 ml M KI and 5 ml of distilled water will be added and after the swirling of the flask, 5 ml of 3% H2O2 will be added. After the times have been recorded, data collection should now be complete.

Distillation of the first product began at 83 °C. A Pasteur pipette was used to remove 1-ml of the distillate into a vial. A second vial was filled with distillate until it reached 1-ml. As the second vial is being filled, observe the temperature and remove the apparatus from the heat source if there is an observed drop in temperature.

Distillation. Transfer the clear liquid to a dry 25-mL round-bottom flask using a Pasteur pipet. Add a boiling stone and distill the crude t-pentyl chloride in a dry apparatus. Collect the pure t-pentyl chloride in a receiver cooled in ice. Collect the material that boils between 78°C and 84°C. Weigh the product and calculate the percentage yield.

Simple distillation is a separation technique which can be used to separate and purify distillates from a liquid mixture which ideally contains one volatile and one non-volatile compound. If such ideal conditions are not possible—as is usually the case—then simple distillation can be applied as long as the liquid in question is composed of compounds that differ in volatility such that their boiling points differ by at least 40 to 50 degrees Celsius. Because

Using a 5 mL pipet, exactly 5 mL of distilled water was added to each of ten test tubes. The level was marked with a masking tape and the water was poured out. The test tubes were marked to their assigned temperatures (45°C, 40°C, 35°C, 30°C and 27°C).

Fractional distillation was accomplished by using the knowledge of the boiling points of both isopropyl acetate and toluene and controlling the temperature of the apparatus so that one substance would boil but not the other. By doing this, isopropyl acetate was able to evaporate first because it has a lower boiling point than toluene. This is why Fraction 1 contained much more isopropyl acetate than it did toluene. By slowly raising the temperature of the apparatus to that of the boiling point of toluene, the distillate collected for Fraction 2 contained more toluene due to the majority of the isopropyl acetate having already evaporated. By using gas chromatography, the exact percentage of each substance in Fractions 1 and 2 were found.

For this experiment, the liquid-liquid extraction and recrystallization technique were used to separate the three compounds: neutral, acid, and base. They were separated on their solubilities into both polar and nonpolar characteristics. The other technique, liquid-solid extraction is used when adding a solvent to a solid. Therefore, the proper technique for this lab that was used was the liquid-liquid extraction and recrystallization technique.

The substances were taken out too late from the distillation assembly and because of this, the compounds mixed once more in the distillation head. Since heptane has a lower boiling point, it would have been our first fraction but because it was not collected quickly enough, the octane managed to boil and the distillate was collected in the distillation head along with the heptane, therefore our results for all fractions were very similar. Also, only three fractions were

The mixture of substances is placed in the flask and heated. Ideally, the substance with the lowest boiling point vaporizes first (see vaporization), the temperature remaining constant until that substance has completely distilled. The vapor is led into the condenser where, on being cooled, it reverts to the liquid (condenses) and runs off into a receiving vessel. The product so obtained is known as the distillate. Those substances having a higher boiling point remain in the flask and constitute the

The boiling points obtained for during fractional distillation also roughly aligned with the correct unknowns, which were Acetone (low boiling point) and Toluene (high boiling point). Any deviation in temperature may have resulted from a thermometer placed too high in the fractional column. The gas chromatography portion of the experiment produced three chromatograms with no apparent impurities. However, fraction A was found to not be purely composed of Acetone, and fraction B was not found to be a 50/50 mixture of Acetone and Toluene, yet, fraction C was found to be pure Toluene. Therefore, the calculated ratio for the mixture, 40.95% acetone and 50.046% Toluene, was greatly off from the true ratio of 25% acetone and 75% Toluene which can again be attributed to the impurities of fraction A. The retention time reported for the Toluene was accurate at .861 minutes, however, the retention time of acetone was slightly off at a value of .651 minutes when the true value is 0.64 minutes. The error of the acetone retention time may be attributed to the small presence of toluene in the fraction A sample. Conclusively, while there is error in all three sets of data the true identity of the high and low boiling point compounds are able to be correctly determined through using the combination of retention time, ratios, and boiling points to analyze which compounds align best with the overall

Steam distillation is a process used often in chemistry to extract a particular component of a mixture at a temperature above the temperature where the substance starts to degrade. As a homogeneous mixture is cooled while being exposed to a component in gaseous form, the partial pressures of the parts (hypothetical pressure of a gas if it had the same volume as the total volume at the same temperature) increases over time. Extraction can occur when the sum of the partial pressures is greater than the atmospheric pressure.