Transactional Distillation Lab Report

There are various techniques to separate a mixture of compounds from each other. One of the commonly used way to isolate compounds from a mixture of two compounds is called extraction. This method of extracting two compounds from each other relies on the different solubility of the compounds in two different solvents.

The process of extraction removes a desired compound from a mixture. Because molecules with similar intermolecular forces are more soluble in one another, organic compounds are usually dissolved in organic solvents. Based on the solubility differences of the organic solution and water, when mixed, two distinct layers form. Sometimes, small amounts of the solvent may dissolve in water. To prevent contamination of the product, a drying agent is added to absorb the water molecule. The organic solvent is evaporated from the organic compound through the use of a rotary evaporator. It is a quick process that reduces the pressure and thus the boiling point of a liquid. In this experiment, eugenol was separated from mixtures containing methylene chloride and hexane. If was predicted that methylene chloride would be the most effective solvents due to its immiscibility to water and low boiling point.

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

The objective of this extraction experiment was to achieve a comprehensive understanding, as well as master the practice, of the technique of separating various individual components of a compound.

5. Substances in a mixture can be separated depending on the substances involved. You can use a magnet to separate a magnetic substance form a non-magnetic one, filtering, and evaporation. For example, when I put the

To carry this out, the initial mixture would be broken up into smaller fractions and each fraction would be distilled according to simple distillation procedures until a pure drop of lower boiling point liquid could be collected—since this pure concentrated compound boils before the other less volatile compound. This obviously is not practical as it yields a very small volume of distillate; however the theory which supports such a procedure is the same theory which the procedure of fractional distillation is built upon. The only difference between the apparatus set-up used for simple distillation and that which is used for fractional distillation is that fractional distillation makes use of a fractional distillation column which is in between the stillhead and the flask containing the pot residue. Some examples of fractional distillation columns are Vigreux columns and Hempel columns. Vigreux columns are marked by indentations while the Hempel column is often packed with material such as glass beads or stainless steel sponge as well as glass tubing sections. The purpose of such a column is a bit muddled at first however when placed in the context of the theory of the series of simple distillations it can be understood that this column simply concatenates the series of simple distillations into one

In 1941 Martin and Synge, described the discovery of liquid-liquid partition chromatography and also laid the foundation of Gas liquid chromatography and High performance liquid chromatography. They also introduced the concept of the Height Equivalent to the Theoretical Plate, which has since been adopted as the measure of Chromatographic efficiency.

Distillation is a method of separating two volatile chemicals on the basis of their differing boiling points. During this lab, students were given 30 mL of an unknown solution containing two colorless chemicals. Because the chemicals may have had a relatively close boiling point, we had to employ a fractional distillation over a simple distillation. By adding a fractionating column between the boiling flask and the condenser, we were able to separate the liquids more efficiently due to the fact that more volatile liquids tend to push towards the top of the fractionating column, thereby leaving the liquid with the lower boiling point towards the bottom. After obtaining the distillates, we utilized a gas chromatograph in order to analyze the volatile substances in the gas phase and determine their composition percentage of the initial solution. Overall, through this lab we were able to enhance our knowledge on the practical utilization of chemical theories, and thus also demonstrated technical fluency involving the equipment.

Chemically active extraction uses the properties of the acid or base to remove it from the solution. The extraction process involves taking the solution, unknown compounds dissolved in organic solvent, and adding basic/acidic solutions to separate the unknown compounds.2 If adding a basic solution, NaOH (aq), causes a product in the aqueous layer, then this unknown is acidic, and the opposite happens with acidic solution, HCl (aq), and a basic unknown. Once separated, the unknowns need to be purified.

The purpose of this experiment was to separate a two component mixture using fractional distillation. Distillation is a process of vaporization than condensation of a substance, used primarily to separate substances from a mixture when there are different boiling points. Fractional distillation is when the mixture has multiple substances with similar boiling points, and a fractional column is used to create multiple vaporization/condensation cycles. Fractional distillation is important when two or more substances need to be separated, but they have similar boiling points.

The purpose of this experiment was to use solvent extraction techniques in order to separate a mixture consisting of a carboxylic acid (p-toulic acid), a phenol (p-tert-butylphenol), and a neutral compound (acetanilide). Extraction is the process of selectively dissolving one or more of the compounds of a mixture into an appropriate solvent, the solution that contains these dissolved compounds is called an extract (Manion, 2004).

     Conventional Liquid Chromatography is most commonly used in preparative scale work to purify and isolate some components of a mixture. It’s also used in ultra trace separations where small disposable columns are used once and then discarded. Analytical separations of solutions for detection or quantification typically use more sophisticated high-pressure liquid chromatography instruments.

The main objective of the distillation lab was to identify the composition of an unknown binary solution. The only known component is that the boiling point of the two components were at least 40˚C apart in boiling points. Due to the difference in boiling points, fractional distillation would be an easy way to determine the identity of each component of the binary solution. In the experiment, 30mL of the unknown binary solution was ran through the fractional distillation apparatus. As the solution boiled, gas from the unknown solution ran through the column, which had a temperature gradient to allow rapid and repeated distillations, and one of the components were isolated. By recording the temperature and amount of

Gel-Filtration Chromatography is a commonly used method used in order purify a protein from a mixture, by means of separations. Different biomolecules differ in size, or their molecular weight. In the gel matrix inside the chromatography column, there are gel beads which are porous to allow certain sized molecules to enter. The molecules that are able to enter the pores of the gel, are held in stationary phase and will elute from the column later on, these are usually smaller, to medium sized molecules. Larger molecules that are not able to fit in the pores will elute out of the column first, they are involved in mobile phase where they just go straight through the column without interacting with the gel beads. Smaller molecules will have a higher elution volume, while the larger molecules will have a lower elution volume. The volume to elute the protein is inversely proportional to the molecules size.

1. Obtain a sample of the mixture. The mixture you will separate contains three components: NaCl, NH4Cl, and SiO2. Their separation will be accomplished by heating the mixture to sub-lime the NH4Cl, extracting the NaCl with water, and drying the remaining SiO2.