Experiment: Analysing molar mass of Aspirin Essay

IntroductionIn 1899 the Bayer Company of Germany introduced the acetate rayon ester of salicylic acid naming it, Aspirin. Aspirin is an acid, it can be titrated with a base such as atomic number 11 hydroxide to the equivalence point. The side by side(p) chemical equation describe the acid-base reaction that will be nonice in this experiment.H-Aspirin + NaOH Na-Aspirin + H2O(acid) (base) (salt)The above chemical equation is balanced as written. An indicant will be used to provide a expressive style to visually determine the endpoint of the titration. Phenolphthalein changes from colourless to a faint pinko while bromothymol blue changes from yellow to a faint blue at a pH of around 8.AimTo calculate the molar chain reactor of AspirinHypothesisThe chemical formula of Aspirin is C9H8O4. It can alike be written as C6H5(OCOCH3)COOH. In this experiment, Aspirin, which is an acid, will react with sodium hydroxide, NaOH in an acid-base reaction to produce salt and water. This anal ysis makes use the point that acetylsalicylic acid is a monoprotic acid and in that locationfore reacts with NaOH according to the equation endThe experimental molar mass of Aspirin, C6H5(OCOCH3)COOH is close to the theoretical jimmy. The difference in the midst of the experimental value and the accepted value is not genuinely big. However, there are difference between the experimental molar mass of acetylsalicylic acid when employ phenolphthalein and bromothymol blue as indicator. The obtained molar mass of aspirin when victimisation phenolphthalein indicator is small than using bromothymol blue as indicator. The difference with the theoretical value is also less. Due to this difference, the percentage error when using phenolphthalein is smaller than bromothymol blue. Therefore, phenolphthalein is a better indicator in this acid-base titration reaction. This is because the final pH or the endpoint of titration lies in between pH range of phenolphthalein that is 8.2-10.0 and not in bromothymol blue which is 6.0-7.6 . This is the reason why phenolphthalein indicator is able to produce much accurate result than bromothymol blue.EvaluationThere are some weaknesses that were detected throughout the experiment. Firstly, the volume of indicator are not fix in this experiment. Using drops is not really suitable as it may sophisticate the volume of indicator in this experiment. The difference may not really big but it still can affect the final result.Secondly, the compartmentalization of aspirin, C6H5(OCOCH3)COOH and sodium hydroxide, NaOH is not stirred during the titration. This may produce uneven and not uniform result as the NaOH is not totally mix with the aspirin. The neutralisation reaction process may only occur on the surface of the aspirin solution.Having said that, this experiment is successfully analyzing the molar mass of aspirin. The experimental value is close to the theoretical value.Further reformmentIn order to improve the results o f the future experiments, several ways can be implemented. Firstly, the volume of indicator use should be fixed instead of using drops. By using this way, the level of uncertainty of the final results can be reduced. Besides that, the sort of aspirin solution and NaOH need to be stirred throughout the titration process. more than uniform results can be obtained by implementing this method.