Discussion
As part of the experiment, the percent composition of each component of the mixture was calculated. 51% of the components were retrieved from filtration while 49% of the solvents were retrieved from dissolving the components in a solvent.
The original mixture was one globular solid-like structure. The first step, to separate the mineral oil from the mixture, was achieved by placing the mixture into ethyl acetate. Mineral oil is the only substance in the mixture that dissolves in non-polar solvents like ethyl acetate, so this helped separate that part from the rest. To get oil by itself, the ethyl acetate must also be boiled off. Mineral oil’s boiling point is much higher than ethyl acetate’s, so it was a good solvent for this process. The remaining ethyl acetate would change states (from liquid to gas) while the mineral oil would remain in its liquid state. The rest of the mixture (the sand, KNO3, and CuSO4) would remain solid and be caught on the filter paper while the dissolved oil and ethyl acetate would go through into the flask. Sand is a network solid that does not dissolve easily; it has such strong bonds that only a strong acid can break. Potassium nitrate and copper sulfate do dissolve in polar substances, so using water as a solvent would be logical. After heating the mixture of sand, potassium
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Potassium nitrate has a lower solubility in solution at lower temperatures compared to copper sulfate. Cooling the mixture to freezing temperatures allows more of the bonds of potassium nitrate to re-associate and become a solid, allowing it to be extracted via vacuum filtration. Copper sulfate’s bonds stay disassociated more often in lower temperatures of water, so it would flow through the filter paper with the water. If the temperature of that remaining mixture were continually lowered, it would precipitate and could be extracted via vacuum filtration as
Because salt dissolves in water, we added water to the salt and sand mixture. Sand is insoluble in water making the sand not dissolve. The mixture containing of sand and salt water was then filtered with filter paper. The filter paper allowed the salt water to pass through because it is a liquid while not allowing sand to pass through because it is a solid. The salt water was then collected in a pre-weighed 250-mL (67.88 gram) beaker while the sand and filter paper was put in a pre-weighed (52.02 gram) 100-mL beaker. The water was then evaporated because we left both beakers to dry overnight.
The crude product was washed by taking the reaction product in the separatory funnel and adding 23 mL of deionized H2O. The mixture was shaken and allowed to settle until layers were observable. The top layer was the desired product and approximately 25 mL of aqueous layer was extracted from the separatory funnel. Next, 25 mL of 5% NaHCO3 was added to the separatory funnel in order to neutralize the acid. This mixture was swirled, plugged with the stopper and inverted. Built-up gas was released by turning the stopcock to its opened and closed positions, releasing CO2 by-product. This was done four times in one minute intervals. The solution was allowed to settle until layers were observable. The bottom layer that contained salt, base and water was extracted from the separatory funnel. The crude product was washed again as mentioned previously.
| Can see particles of both. When mixed with water salt dissolves and sand is left.After filter sand is left and salt-water goes through.After evaporations of salt-water, salt is only left in dish.
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.
Yes, because the solution seen was still blue meaning that not all the copper chloride was extracted from the beaker.
In the separating funnel, a heterogeneous mixture was formed: resulting in an organic layer (top) and a solvent layer (bottom). This effectively allowed the draining of the solvent, in order to isolate the organic layer, the impure ester (1-pentyl ethanoate)
Since we obtain an unknown proportion of a mixture, it’s important to mention that a mixture is a result of a combination of two or more pure substances that do not react chemically. The physical properties of a mixture depend on its composition because the amounts of each substance making up a mixture can vary. By taking advantage of the unique physical properties of individual components within a mixture, it should be possible to separate a mixture into its components. Mixtures have the following fundamental properties:
In this experiment, the pKa, dissociation constant, of 2-naphthol was determined by measuring the UV-visible absorption spectra of solution of the acid at different pH values.
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.
When the crude product is transferred to a separatory funnel, it is washed with 10 ml of water. When the solution forms two layers, the bottom aqueous layer is disposed of.
Assign one member of the group to gently stir solution with a thermometer (See figure 2)
2. Add about 20 mL of distilled water and stir the mixture with a glass stirring rod to dissolve the sample. There may be a small amount of insoluble residue. If your sample does not dissolve completely, remove the insoluble material by filtration.
Qualitative analysis is the use of experimental processes to identify the chemical parts of a substance. The knowledge of the meaning of soluble and insoluble is key to completing this experiment correctly and accurately. Soluble means that a compound readily dissolves in water and insoluble means that compounds do not dissolve in water. A precipitate is formed when two soluble compounds combine to form an insoluble compound. All nitrate solutions are soluble; therefore, the known solution was formed by dissolving nitrate salts of all the cations in the experiment in De-Ionized water. A centrifuge was used in each step of the experiment to spin
The original pigment also dissolves into the solvent. The problem being presented is which component has the higher percent composition by mass in the sand, salt, and iron mixture. The purpose of the experiment was to determine the percent composition by mass of each substance in the sand, salt, and iron mixture by separating those using different methods and then figuring out which substance has the highest percent
Part 1: Esters aromas are very distinct and often pleasant, they are often used in food aroma and fragrances.1 Esters chemical properties are distinguished by their low molecular weight and low boiling points, caused by their dipole-dipole and dispersion interaction.2 Esters are the result of a condensation reaction, in which a carboxylic acid, an alcohol, and an acid catalyst react to create a water molecule and an ester.