Extraction of Benzoic Acid

Introduction The theory behind the extraction of a re closure containing benzoic acid, cellulose, and methyl radical orange tree involves many components pertaining to the fundamental ideas of solubility and polarity. apply the concepts of like dissolving like and acid base reactions, a solution of total acid (benzoic acid), a water soluble blend cellulose, and an organic soluble compound methyl orange, lowlife be separated and benzoic acid can be isolated by a order of extraction.At the fundamental level, organic solvents separate from sedimentary solutions based on their variable densities, typically the organic stratum being less dense and because on top of the aqueous layer1. Therefore any solutes in those solutions ar also separated and can be isolated from one another. This phenomenon is the base of operations for the liquid-liquid extraction and leads into the concept of the partition coefficient. According to MtCg the ratio of concentrations of a solute in each l ayer is defined by the partition coefficient K, where K = C2 / C1.The statistical distribution coefficient can therefore be viewed as the ratio of the concentration of the compound in organic solvent to the concentration of the same compound in aqueous solution. This constant allows for the calculation of dissolved compound in each layer of the solution, so that afterwards several extractions, the yield can be sufficient for the purposes of the experiment. A second type of extraction, acid-base extraction, involves the addition of acids and bases in solutions to mixed bag the polarity of organic acids and bases to their corresponding water-soluble salts2.This allows us to take return of the liquid-liquid extraction to separate organic acids and bases from solution mixtures. Such extraction can be considered chemically active extraction because the polarity of one center field is altered to increase solubility in water. This type of extraction is infallible when both compounds a re non-polar and dissolved well in organic solvents. For look into 1 Extraction of Benzoic Acid, a solution of benzoic acid, cellulose and methyl orange will first be added to ether, heated and filtered to separate the organic non-water-soluble cellulose leaving benzoic acid nd methyl orange. wherefore after adding NaOH, the benzoic acid will react to form the water-soluble salt, sodium benzoate, which can be separated via the liquid extraction technique. in conclusion adding HCl to the aqueous sodium benzoate will cause the acid-base reaction to undergo restoring benzoic acid in the organic layer and NaCl in the water layer. Reagent dining table Experimental To start, a solution of diethyl ether was mixed with 4. 06g of crude benzoic acid with two impurities.Boiling stones were added to the mixture and heated over the steam bathtub until the ether solution began to boil. Once the solution was boiling to most expeditiously dissolve the inorganic parts of the solution, the eth er insoluble corporal was filtered out(p) of solution using the Buchner funnel clean filtration technique. The filtrate ether stay was added to a separatory funnel with 30mL of 1M NaOH, mixed and vented properly, and then rested as the solution settled into separate organic and aqueous layers.The bottom layer (aqueous) was drained from the separatory funnel into a beaker and another 30mL of NaOH was added to the left over ether, swirled and vented, separated, and the aqueous layer drained off into the same beaker as the first aqueous extraction. Next the aqueous solution that was collected was cooled on ice and 50mL of chilled 6M HCl was added to the mixture. At this point, a Bruchner funnel was used to collect the solid precipitate via vacuum filtration and those collected crystals were weighed out and set aside for the recrystalization of benzoic acid.Results The most consequential measurements do during this lab were the initial weight of the crude benzoic acid, which was 4. 06g, and the cumulation of the crystals after the separation from the two impurities, 4. 88g. The fact that the crystals weighed more than the starting material can be accounted for based on the lack of proper drying metre for the crystals, and will be accounted for when calculating the percent composition.Discussion After the results of the lab, there were a few points to consider in the final analysis. First off, and most distinguishedly, after the crystals were obtained from the aqueous solution obtained by adding NaOH, the crystals were used immediately for the recrystalization and were not wedded the proper time to dry out, so the weight of the wet crystals moldiness be used to calculate the percentage composition, which will be inaccurate.Another important note was after the HCl was added to the aqueous solution, the solution turned bright pink, indicating that or so of the methyl orange, which should have remained in the organic layer in the separatory funnel, had made it into our aqueous solution. To counteract this, when the vacuum filtration technique was used, the solid precipitate was swear out with distiller water to ensure the crystals did not contain a pink bear upon to them.The reason this lab works was because the first filtration got rid of the organic insoluble cellulose leaving methyl orange and benzoic acid in the ether mixture. Then, using the acid-base extraction technique, benzoic acid was altered to sodium benzoate, adaptation it soluble in aqueous solution, which allowed for the separation of the sodium benzoate from the methyl orange (still dissolved in ether) and then the reformation of benzoic acid by adding a strong acid to the aqueous dissolved salt. References MtCg pg. 129 MtCg pg. 131