Mass of Aspirin tablet: 0.357 g

10 mL of 1 M NaOH was added to the aspirin tablet in a 125 mL Erlenmeyer flask and heated to a boil. The solution was transferred to a 100 mL volumetric flask and the flask was filled to the mark with DI water.

1 mL of the solution was pipetted into a 50 mL volumetric flask; the flask was filled to the mark with FeCl3 solution.

I'm trying to find the mass in grams of ASA in the aspirin unknown. The concentration I got from my Beer's Law plot was 0.562 M. How do I go about finding the mass?

1 answer

Okay, I guess I should rephrase my question.

I know how to go from moles to grams. My REAL question is the dilution part. When I do M1V1 = M2V2, I do (0.562 M)(0.001 L) = (x)(0.05 L), but that doesn't seem right, because the answer is 0.01124 mol and when I convert that to grams of ASA, I get 2.025 g. I have to find the mass % of ASA in aspirin and my aspirin mass was 0.357g, so it doesn't seem right...