Lab report I chem 2753

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East Carolina University *

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2753

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Chemistry

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Dec 6, 2023

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1 Corina Keever Chem 2753 September 23 Extraction and Solubility Section 1: Both solubility and extractions are fundamental concepts in chemistry and have a wide range of practical applications in various scientific and industrial fields. The goal of this experiment was to have a mixture of two solvents and a solute and extract one solvent from the mixture. The choice of solvents, temperature, and other conditions can be optimized to achieve specific separation and purification goals in an extraction. When dissolving solvents into solutes the chemical properties of the solute and solvent, such as polarity and intermolecular forces, play a significant role in determining solubility. The solubility properties of a compound can be predicted based on the compound's molecular forces. Polar compounds tend to dissolve in polar solvents while non-polar compounds tend to dissolve in non-polar solvents. This can be important in liquid-liquid extractions because, a solvent is used to selectively dissolve and transfer a particular component from one liquid phase (the original mixture) to another liquid phase (the solvent). The choice of solvent and its selectivity for the desired component are crucial in this process. The possible solutes for this experiment were benzil, benzoic acid, and sodium benzoate. The possible solvents for this investigation were Sodium Hydroxide, HCl, Diethyl Ether, and Water. To verify which solvents and solutes were going to be used in the extraction a solubility test was performed by dissolving each solute into a solvent. To collect this data 0.05 g of each solid was dissolved into 2 mL of each solvent. Each sample was labeled and then set out for a week to see the results. From this sample the samples with diethyl ether completely evaporated. The data from this procedure as shown in table 1.1 concluded the best solvents for the extraction were benzoic acid and benzil and the solutes being used will be diethyl ether and sodium hydroxide neutralized with HCl. Melting point can be used to

2 determine the purity of a substance, because the more energy required to break down the structure of a impure substance than a pure substance. The major findings of this experiment was since the recovered sodium benzoate was aqueous and benzil had a percent yield of 204%.The benzil started melting at 89° C and never fully melted an extraction of sodium benzoate and benzil was not preformed. Section 2: To start the extraction 0.25 mg of each solute (benzil and sodium benzoate) was weighed out. Then 20 mL of diethyl ether was measured using a graduated cylinder. The diethyl ether mixture was chosen as our solvent since it is more polar than NaOH and benzil and benzoic acid are less polar. The diethyl ether will still dissolve both benzil and benzoic acid. The mixture was added to the separatory funnel and then the NaOH to pull out the more polar substance, benzoic acid. The flask was inverted to ensure all components were completely dissolved together and then the gas was release. Placing the funnel back into the ring stand the NaOH and benzoic acid layer was poured into a beaker. This step was repeated twice to ensure all the sodium benzoate was extracted from the diethyl ether. The diethyl ether was poured into a beaker. The NaOH was then neutralized using 6M HCL and poured into a beaker, both mixtures were labeled accordingly and stored for one week. Section 3: Table 1.1 (Solubility Results) Diethyl Ether NaOH Water Benzil I I I Sodium Benzoate I I S Benzoic acid S S I After waiting a week, the data collected is located in Table 1.2. Based on the experiment and data collected an extraction was not preformed. From the results a recovery mass of 0.51 g of Benzil was

3 recovered. Using the starting mass of Benzil and the recovered mass of benzil you can find the percent yield: 0.51 g ( Recovered Mass ) 0.25 g ( Starting Mass ) x 100 = 204% . The first sign from the results is that the NaOH and Benzoic acid did not evaporate fully leaving an aqueous mixture. This could have been solved by doing another extraction of the NaOH and Benzoic acid with diethyl ether to ensure it would evaporate in the given week. The next indication was that the percent yields of the Benzil was 204% meaning there was something else in the recovered substance. The melting point for the benzil started at 89 ° and did not fully melt. The melting point of a substance can be used to determine the purity of a substance. For benzil the experimental melting point of is between 94 °-97 ° C according to chemspider . The melting point being extremely high could mean we have either sodium benzoate or diethyl ether in the benzil. Meaning the structure of the benzil yielded was not the purest form and the extraction was not preformed. Comparing the results to other groups, most were results were similar. The main solvents being used were benzoic acid and benzil, however some people chose to use water instead of sodium hyd. The results from three of the other groups also had unevaporated liquid in their beakers, and none of these groups had their benzoic acid in diethyl ether. The percentage yield of my groups benzil was 204% and a group that used the same solvents and solutes as we did got a percent yield of 206%, which is very close. The groups that did leave the benzoic acid in diethyl ether did evaporate, so a calculating yield percentage and finding the melting point was possible. Tabel 1.2 (Extraction results) Sodium Benzoate Benzil Mass 18.63 g 0.51g Percent yeild N/A 204%

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