Aspirin contains a chemical named acetylsalicylic acid (CH3COOC6H4COOH). This experiment’s purpose is to determine the percent of acetylsalicylic acid in tablets of Bayer Aspirin and Bufferin by using the method called a “back titration”. A known amount of standardized sodium hydroxide (NaOH) will be added to a known amount of Aspirin/Bufferin to hydrolyze the acetylsalicylic acid.
First, Kosuke and I started experiment for Aspirin. However, when we reached to “Determination of the amount of NaOH remaining”, serious problem occurred. That problem was solution didn’t turn pink. Even I drop some phenolphthalein. When Ms. M checked our solution, it was acidic. We thought we were doing everything all right but this problem occurred. One problem that we can think about is misplacing of HCL and NaOH beakers. So next time, we’ll make label for each beaker. Regardlessly, by this problem, we lose lots of time. And also, we took time when we pipetting solution. Before I change old bulb to new bulb, it didn’t work well. New bulb worked very well so next time when I use pipette and bulb, I will choose new bulb for pipetting.
We missed first experiment so we restarted the experiment using Bufferin. This time, we really keep on eye on everything. And we did carefully. So this time, the color turned clear pink when we added phenolphthalein. So, we thought finally our experiment succeed. In fact, as I wrote in the conclusion, our results for Question4 and Question5 were completely off the target.
So, when we think for problems, I’m not sure why the result varies so differently. However, we missed first try in this experiment, so we didn’t had time. It’s true that we hurried in the step of simmering aspirin tablets. We may didn’t simmer solution enough so, this may cause problem in our result. So, even we thought second try succeed, actually our experiment failed in second try. When we do lab next time, we will become more carefully and never try not to miss experiment. Because if we miss experiment one time, automatically, we have to hurry in second try so there high possibility of error occurring. So next time, we want to do experiment securely.
[ C H E M I S T R Y ]
A NALYSIS OF THE PURITY OF
Determine the percent of acetylsalicylic acid in tablets of Bayer Aspirin and Bufferin.
Aspirin contains a chemical named acetylsalicylic acid (CH3COOC6H4COOH). This experiment's purpose is to determine the percent of acetylsalicylic acid in tablets of Bayer Aspirin and Bufferin by using the method called a "back titration". A known amount of standardized sodium hydroxide (NaOH) will be added to a known amount o..