An aspirin tablet weighing 0.548 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.
mass aspirin = 0.548*0.628 = ??
??/180.16 = xx mols aspirin = 0.00191 mols. Check my arithmetic.
diluted to 250 so 0.00191 mols/250 = xx mols/mL.
Take 3 mL of that solution and make to mark of 100, so we now have xx mols/mL x 3 mL/100 mL = yy mols/mL.
We want mols /L so multiply yy mols/mL *1000 to obtain mols/L = molarity.
take the amount of grams (.548) and multiply it by .628
You then get .37373 (this is the concentration of ASA that the problem is focusing on)
So you divide .37373 by 180.16 to figure out the amount of moles= .002075, divide this number by .250L to get your Molarity, your concentration= .008299mols/L
then you plug this in the formula
M1 x V1 = M2 x V2
M1= .008299
V1= .003 L (the amount of the solution you use)
M2= ? (this is our variable that we are trying to find)
V2= .100 L
your M2 comes out to be .000249mols/L
ANd that's the answer!!! (:
To calculate the concentration of the diluted solution, you need to follow these steps:
1. Calculate the mass of aspirin in the tablet. Since the tablet contains 68.2% ASA by mass, you can find the mass of ASA by multiplying the total mass of the tablet (0.548 g) by 0.682.
Mass of ASA = 0.548 g * 0.682 = 0.374216 g
2. Convert the mass of ASA to moles. To do this, divide the mass of ASA by the molar mass of ASA, which is 180.16 g/mol.
Moles of ASA = 0.374216 g / 180.16 g/mol = 0.002077 mol
3. Calculate the molarity of the diluted solution. Since the solution has been diluted to a final volume of 100 mL, you need to find the number of moles per milliliter (mol/mL).
Moles per mL = moles of ASA / volume of solution (in mL)
Moles per mL = 0.002077 mol / 250 mL = 0.00000831 mol/mL
4. Finally, convert the molarity from mol/mL to mol/L by multiplying by 1000.
Molarity = 0.00000831 mol/mL * 1000 = 0.00831 M
Therefore, the concentration of the diluted solution is 0.00831 M.