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?
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...
To find the mass of acetylsalicylic acid (ASA) in the aspirin tablet, you can use the following steps:
1. Calculate the number of moles of NaOH used: Since you added 10 mL of 1 M NaOH, the moles of NaOH can be calculated as:
Moles of NaOH = Volume of NaOH (L) × Concentration of NaOH (mol/L)
Moles of NaOH = 10 mL ÷ 1000 mL/L × 1 mol/L = 0.01 mol
2. Determine the balanced chemical equation between ASA and NaOH: In this reaction, NaOH reacts with ASA in a 1:1 ratio. The balanced equation is:
NaOH + ASA ⟶ Sodium salt of ASA + Water
Since the molar ratio is 1:1, the moles of ASA will be equal to the moles of NaOH used.
3. Calculate the moles of ASA: The moles of ASA can be determined from the moles of NaOH used, which is 0.01 mol.
4. Convert moles of ASA to grams: To convert moles of ASA to grams, you need to use the molar mass of ASA. The molar mass of ASA (acetylsalicylic acid) is 180.16 g/mol. Multiply the moles of ASA by the molar mass to find the mass in grams:
Mass of ASA = Moles of ASA × Molar mass of ASA
Mass of ASA = 0.01 mol × 180.16 g/mol = 1.8016 g
Therefore, the mass of acetylsalicylic acid (ASA) in the aspirin tablet is approximately 1.8016 grams.