Evaporating Preparation

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

14 mL of 9 M H2SO4 was added to the separatory funnel and the mixture was shaken. The layers were given a small amount of time to separate. The remaining n-butyl alcohol was extracted by the H2SO4 solution therefore, there was only one organic top layer. The lower aqueous layer was drained and discarded. 14 mL of H2O was added to the separatory funnel. A stopper was placed on the separatory funnel and it was shaken while being vented occasionally. The layers separated and the lower layer which contained the n-butyl bromide was drained into a smaller beaker. The aqueous layer was then discarded after ensuring that the correct layer had been saved by completing the "water drop test" (adding a drop of water to the drained liquid and if the water dissolves, it confirms that it is an aqueous layer). The alkyl halide was then returned to the separatory funnel. 14 mL of saturated aqeous sodium bicarbonate was added a little at a time while the separatory funnel was being swirled. A stopper was placed on the funnel and it was shaken for 1 minute while being vented frequently to relieve any pressure that was being produced. The lower alkyl halide layer was drained into a dry Erlenmeyer flask and 1.0 g of anhydrous calcium chloride was added to dry the solution. A stopper was placed on the Erlenmeyer flask and the contents were swirled until the liquid was clear. For the distillation

In this lab, a mixture of three solids was separated to their individual components through decantation,

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

This experiment was done in order to understand both fractional distillations and gas chromatography. In addition, this experiment was done to separate and identify two liquids that made up an unknown mixture. Gas chromatography was used to figure out the ratio of these two liquids.

A small beaker was placed under the arm of the distillation head to catch the distillate. Foil was wrapped around the neck of the round-bottomed flask and a wet paper towel was wrapped around the arm of the distillation head to create a condenser. The flask was heated gently so that the distillate dropped at a rate of two drops per minute. The temperature was recorded as every drop was collected. The distillation began at around 55.0 ℃. The distillation was stopped after 29 drops were collected to prevent the solution from being distilled to dryness. See attached data. The known boiling point of 1-butanol is 117.5 ℃ (Lemonds). The known boiling point of 1-propanol is 97 ℃ (Thiyagarajan). The known boiling point of acetone is 56 ℃ (Forss). The known boiling point of 2-butanone is 79.6 ℃ (Jiang). For unknown #3 the boiling point of the first substance seemed to be around 56 ℃ and the boiling point of the second substance seemed to be around 111 ℃. Therefore unknown #3 seemed to be a mixture of acetone and 1-butanol.

With the purpose of the experiment being to identify the 30 mL of unknown liquid, the theoretical basis of simple and fractional distillation must be deconstructed and applied to the data obtained describing the liquid in question.

Multiple extractions with smaller volumes are more efficient than a single extraction at a one large volume. When an organic solvent is used to extract a compound from the aqueous solvent, smaller volumes will result in a better extraction. The success upon the collection of the crude material is depended on how well the water is absorbed by the anhydrous drying material. The presence of the drying material correlates with the vapor pressure of the other compound. When the vapor pressure is low, there is a smaller amount of moisture in the gas produced. Once the anhydrous material is added and clumping was avoided, the evaporation of the added organic substance can proceed. The final material collected can be physically identified by the final color of the precipitate. A greenish- white precipitate is most likely identified to be pure, and a brownish color indicates that the collected material is wet, and not

1.) Briefly explain the concept of steam distillation. What is the difference between a simple distillation and a steam distillation? When a mixture of two immiscible liquids are distilled it is referred to as codistillation. This process is referred to as steam distillation when one of the liquids is water. This distillation is used to separate organic liquids from natural products and reaction mixtures in which the final product results in high boiling residues such as tars, inorganic salts, and other relatively involatile components. It is useful in isolating volatile oils from various parts of plants and not useful in the final purification of a

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.

The boiling range of the 1-pentyl ethanoate distillate was approximately between 149-151°C. This was indicated by the formation of the distillate and when the mixture of the purified 1-pentyl ethanoate started to vigorously

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.

This liquid is clear, has a fluid consistency similar to water, and has a strong odour that reminds me of alcohol.

The purpose of this experiment is to separate a mixture of salicylic acid and naphthalene using extraction, recrystallization and sublimation techniques. Extraction is the separation of compounds from a mixture based on their relative solubilities in different solvents. Sublimation is the process of separation by which a substance transitions from the solid phase into the gas phase, skipping the liquid phase. Recrystallization involves dissolving a substance in an appropriate solvent then crystallizing it as it cools (impurities remain in solution). The melting points of the substances were determined in order to assess their purity and the percent recovery of pure naphthalene and salicylic acid were calculated. According to the results, the melting point of pure naphthalene was between 86°C -89°C range, whereas for pure salicylic acid was 167°C -170°C. Both determined melting points were higher compared to the literature value of 80.26°C and 158.6°C for pure naphthalene and salicylic acid respectively. Lastly, the percent recovery for pure naphthalene and salicylic acid were 17.7% and 71.2% accordingly.

Once cooled, the mixture was then transferred to a separatory funnel using the funnel while avoiding adding the boiling chip. 10 ml of water was then added to the mixture. The mixture was gently shaken and the phases were allowed to separate. The funnel was then unstopped and the lower aqueous phase was drained into a beaker. 5 ml of 5% aqueous NaHCO3 was added and then shaken gently. A great deal of caution was taken into consideration because of the production of carbon dioxide gas which caused pressure to develop inside the funnel. The pressure needed to be released so the funnel was vented frequently. The phases were allowed to separate and the lower aqueous phases was drained into the beaker. After draining, 5 ml of saturated NaCl was added to the funnel and then shaken gently. Once again, the phases were allowed to separate and the lower aqueous phase was drained into a beaker. An ester product was produced and was transferred into a 25 ml Erlenmeyer flask. This organic product was then dried over anhydrous Na2SO4 to trap small amounts of water in its crystal lattices thus removing it from the product. Finally the ester was decanted, so that the drying agent was excluded from the final product.