Synthesis of Aspirin

Abstract The purpose of this lab is to synthesise acetylsalicylic acrimonious ( acetylsalicylic acid) by creating a reply between acetic anhydride and salicylic acrimonious. This was be elegant through the use of recrystallization. Acetic anhydride and salicylic sexually transmitted disease are mixed together, and and so dosageified by the addition of a some drops of backbreaking sulfuric dit, which catalyzed the response. The pct offspring is castd to determine the effectiveness of the reaction in preparing the desire product ( acetylsalicylic acid).The hold in reactant of the equation was salicylic acid. later on the limiting reactant was determined, the suppositional yield of aspirin was calculated at approximately 1.97g. The actual yield was just now around 0.67g, producing a share yield of 34.3%. These results show that the methods use were plainly partially successful at achieving the goal of the experiment (synthesising aspirin). The findings showed that a cetylsalicylic acid raise be produced through a reaction between salicylic acid and acetic anhydride, but that a much lower yield will be produced. A higher yield could surely be achieved if several authors of fallacy were to be eliminated.Introduction Acetylsalicylic acid is commonly employ to alleviate minor aches and song (Wikipedia, Aspirin, 2013). The active metabolite ingredient in acetylsalicylic acid (aspirin) is salicylic acid (Wikipedia, Salicylic acid, 2013), which was first observed by Edward St ace in 1763 (Wikipedia, Aspirin, 2013).Salicylic acid is toxic in turgid quantities but in small doses can be useful for nutriment preservatives and as an antiseptic. Other than being used in the production of aspirin, acetic anhydride is used to convert cellulose to cellulose acetate, a key component in photographic film and other(a) coated materials (Wikipedia, Acetic anhydride, 2013). Sulfuric acid has legion(predicate) applications, such as pigments, explosives, lub ricants, batteries, antifreeze, and detergents. In the synthesis of aspirin, sulfuric acid is in any case used as a catalyst to speed up the reaction (Wikipedia, Sulfuric acid, 2013).Limiting reactants are important in chemical reactions because a reaction cannot proceed without all of the reactants. That is to say, a reaction canonly drop dead until one reactant is used up (Kirk, 2013). portion yields are related to limiting reactants because the formula to solve for percent yield includes theoretical and actual yield. The theoretical yield is the amount of a product formed when the limiting reactant in completely consumed, and is the maximum amount that can be produced from the amount of reactants used in the reaction. The theoretical yield is rarely obtained because of sources of error, side reactions, or other complications. The percent yield is the actual yield of a product given over as a percentage of the theoretical yield (Kirk, 2013).PurposeHow can one prepare aspirin t hrough a reaction between salicylic acid and acetic anhydride?Apparatus(2) 250 mL beaker 10 mL graduated cylinder imbue subject Funnel support Hot plate 25 mL graduated cylinder 50 mL Erlenmeyer flaskfulful Eyedropper pipet Funnel 100 mL beaker Wash bottleMaterialsBoiling chips (calcium carbonate) Acetic anhydride 18M sulfuric acid Ethanol Salicylic acid Distilled wet IceMethod 1. Prepared a peeing bath by half-filling a 250 mL beaker with water and passion it on a hot plate to until it was near boiling. Placed a few boiling chips in the beaker to prevent bumping if the water began to boil. 2. Weighed out 1.5g of salicylic acid on a piece of drivel musical theme. preserve the load on the data sheet. Transferred the salicylic acid to a 50 mL Erlenmeyer flask. 3. Measured out 5.0 mL of acetic anhydride in a graduated cylinder from the fume hood. Recorded the volume of acetic anhydride used on the data sheet. Poured the acetic anhydride into the 50 mL Erlenmeyer flask conta ining the salicylic acid.4. Took the Erlenmeyer flask to the fume hood and added 5 drops of concentrated sulfuric acid to the mixture. 5. Mixed the solution and placed the Erlenmeyer flask in the water bath for about 10 legal proceeding, making sure the Erlenmeyer flask did not tip in the water bath. 6. later on the 10 minutes elapsed, added 2 mL of distilled water with an eyedropper carefully to avoid splatter. Waited 6 minutes, during which season an nut case water mixture was prepared in another 250 mL beaker. 7. After the 6 minutes elapsed, 10 mL of distilled water was added to the Erlenmeyer flask and placed in the ice water, avoiding getting any of the ice water in the Erlenmeyer flask. A precipitate formed as the solution cooled. employ the incision method, in which the bottom of the Erlenmeyer flask is scraped, to speed up the sue of precipitate formation.8. Prepared a piece of pervade paper in a filter funnel and filtered off the precipitate from the Erlenmeyer flas k solution. After the liquid drained through the filter paper, washed the filtrate with dickens 10 mL portions of cold distilled water. When all the water had drained through, the filter paper was removed, and the solid (impure aspirin) was scraped into a dry 100 mL beaker development a clean scoopula.Recrystallization9. Measured out 5 mL of ethanol from the fume hood in a graduated cylinder, and added it to the 100 mL beaker containing the solid aspirin. Swirled the beaker to dissolve as much of the solid as possible, wherefore placed the beaker on the hot plate until the solid completely dissolved. 10. After the soliddissolved, added about 15 mL of distilled water. Prepared another ice water mixture in the 250 mL beaker and placed the 100 mL beaker in the ice water. Waited about 10 minutes. 11. Weighed a piece of filter paper and recorded it on the data sheet. Prepared the filter paper in a funnel and filtered off the precipitate. Rinsed the dirty apparatus good with lots of w ater. After all of the water was filtered through, left the filter paper to dry until the next class. 12. Weighed the piece of filter paper with the aspirin on it. Recorded the weight on the data table. Discarded the aspirin.Results Overall Findings When the salicylic acid and acetic anhydride were mixed, a exsanguinous, powdery solution formed. When the sulfuric acid was added, a clear solution formed that produced heat. After heating, then cooling and excoriation the solution, a discolor precipitate formed. The moisture in the precipitate was filtered nightlong and what was left over was the desired product, aspirin.Qualitative Data The boiling chips (calcium carbonate) were white, opaque crystals. The acetic anhydride was a clear solution with a vinegar-like odour. The salicylic acid was a find, white solid powder. The ethanol was a clear solution with an odour standardized to strong alcohol. The sulfuric acid was a clear solution with a strong odour when heated. The aspirin (acetylsalicylic acid) was a white, solid powder.When the acetic anhydride and salicylic acid were mixed, they produced a white, powdery solution. When the sulfuric acid was added to this solution, it turned clear and was warm. Upon heating the solution and adding water, puffs of smoke were produced. When the solution cooled and the scratching method was used, a white precipitate formed.Quantitative Data Density (Table 1) Substance Density Acetic anhydride 1.08 m/LVolume (Table 2) Substance Volume Acetic anhydride 5.0 mLMolar weight (Table 3) Substance Molar weight Salicylic acid 138.12 g/ seawall Acetic anhydride 102.09 g/mol Acetylsalicylic acid 180.16 g/mol Weight (Table 4) Substance Weight Salicylic acid 1.51 g Acetic anhydride 5.4 g Empty filter paper 1.27 g Filter paper and aspirin 1.946 g Aspirin 0.676 gPercent Yield (Table 5) Substance Percent Yield Aspirin 34.3%Analysis Determine whether the limiting reactant is the salicylic acid or the acetic anhydride. First, convert bot h masses to moles. 1 mole is relate to the molar mass of a substance therefore, the grams of acetic anhydride and grams of salicylic acid must(prenominal) be divided by their molar masses respectively.Molar mass of acetic anhydride = 4(12.01) + 6(1.008) + 3(16) = 102.088g Molar mass of salicylic acid = 7(12.01) + 6(1.008) + 3(16) = 138.118 g Acetic anhydride 5.4g C4H6O3 x 1 mole C4H6O3 l= 0.052895541 moles C4H6O3 102.088g C4H6O3Salicylic acid1.51g C7H6O3 x 1 mole C7H6O3 = 0.01093268 moles C7H6O3 138.118 g C7H6O3Since both acetic anhydride and salicylic acid have a coefficient of 1, the smaller sum up is the limiting reactant. Therefore, salicylic acid is the limiting reactant of the reaction. Next, calculate the theoretical yield of aspirin by converting the mass of the limiting reactant to grams of aspirin. 1.51g C7H6O3 x 1 mole C7H6O3 x 1 mole C9H8O4 x 180.154 g C9H8O4138.118 g C7H6O3 1 mol C7H6O31 mol C9H8O4 = 1.969566168g AspirinUsing the theoretical yield and the actual yiel d (from the data table), calculate the percent yield.Percent yield = Actual yield x 100 = l 0.676g l x 100 = 34.3% Theoretical yield1.969566168gDiscussion Sources of error that were possibly expose in the synthesis of aspirin lab are an improperly set balance, an inaccurate hot plate, contaminationof the substances, age of the substances, or contamination of the glassware. away calibrations of the hot plate or balance could have shown higher or lower quantitative data which would have affected the results by producing ein truth a higher or lower percent yield. A contamination of the substances used or the glassware could have caused the substances to react differently with from each one other, again causing the percent yield to change depending on how the contamination affected the substances by producing a higher or lower percent yield.Another source of error could have been due to the transport of the aspirin from the Erlenmeyer flask after cooling to the funnel to be filter ed. Some of the aspirin may have been lost or left behind and that would have showed a lower percent yield. The accuracy of this lab could be improved with to a greater extent precise equipment, allowing the experimenter to be more confident in the accuracy of the measurements obtained. season the aspirin was left overnight to allow time for the moisture to be filtered out, the air could have been a contaminant.A way to get rid of the source of error would be to keep the samples in a more stranded area where there is a smaller chance of contamination. Aspirin has many another(prenominal) real-life applications. It is a pain reliever and a non-steroidal anti-inflammatory (NSAID). It has become very common as an antiplatelet to prevent blood clot formation and is used to prevent heart attacks and strokes. It has been present for over one hundred years and is one of the most widely used medications in the world. ConclusionThe of import objective of the synthesis of aspirin lab was so produce aspirin (acetylsalicylic acid) through the reaction of salicylic acid and acetic anhydride. The methods used included recrystallization and scratching to produce a precipitate, which was then filtered to remove any excess moisture. The results displayed a percent yield of 34.3%, from a theoretical yield of about 1.97g of aspirin and an actual yield of approximately 0.68g of aspirin. Upon completion of the lab, analysis, and calculations, it is evident that the synthesis of aspirin is possible using these methods but that the yield will be comparatively low.