An aspirin tablet weighing 0.475 g has been analyzed and contains 68.2 % ASA (180.16 g/mol) by mass. A student dissolved
the tablet in hot NaOH and the cooled solution was diluted with DI water to the mark in a 250 mL volumetric flask. Exactly 3.00 mL
of the solution was pipetted into a 100 mL volumetric flask and diluted to the mark with FeCl3 solution.
The concentration of the diluted solution is ?
M.
You don't say concentration of what. or in what units? I assume you mean the concentration of ASA.
Mass ASA in the 250 mL flask was 0.475*0.682 = ??g
Then 3.00 mL was taken and diluted to 100 mL. The mass in the 100 mL flask is
??g x 3.00/250 = xx grams ASA.
If you want the concentration in g/mL it is xx g/100 mL.
If you want it in mols/L, then convert grams in the 100 mL flask to mols and divide by liters (0.1 L).
Post your work if you get stuck.
To calculate the concentration of the diluted ASA solution, we need to follow a few steps.
Step 1: Calculate the mass of ASA in the 250 mL flask.
Given that the aspirin tablet weighs 0.475 g and it contains 68.2% ASA by mass, we can calculate the mass of ASA in the tablet as follows:
Mass of ASA = 0.475 g * 0.682 = 0.32365 g
Step 2: Calculate the mass of ASA in the 100 mL flask.
We took exactly 3.00 mL of the solution from the 250 mL flask and diluted it to 100 mL. To find the mass of ASA in the 100 mL flask, we use the mass of ASA in the 250 mL flask and the ratio of volumes:
Mass of ASA in 100 mL flask = (0.32365 g * 3.00 mL) / 250 mL = 0.0038832 g
Step 3: Calculate the concentration of the diluted solution.
If you want the concentration in g/mL, divide the mass of ASA in the 100 mL flask by the volume of the flask:
Concentration of ASA = 0.0038832 g / 100 mL = 0.038832 g/mL
If you want the concentration in mol/L (M), you need to convert the mass of ASA in the 100 mL flask to moles and divide by the volume in liters (0.1 L):
Molar concentration of ASA = (0.0038832 g / 180.16 g/mol) / 0.1 L = 0.021524 M
So, the concentration of the diluted ASA solution is 0.038832 g/mL or 0.021524 M.