An aspirin tablet weighing 0.502 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 FeCl_3 solution.
The concentration of the diluted solution is
2.00g of NaOH are dissolved in water to make 5.00L of solution. What is the concentration of hydronium ions, [H3O+], in this solution?
To find the concentration of the diluted solution, you will need to calculate the number of moles of aspirin (acetylsalicylic acid, ASA) in the original tablet and then divide by the volume of the diluted solution.
Here's how you can calculate it step by step:
Step 1: Calculate the mass of ASA in the tablet:
The tablet weighs 0.502 g, and it is 68.2% ASA by mass. So, to calculate the mass of ASA in the tablet, you can multiply the total weight of the tablet by the percentage of ASA: 0.502 g x 0.682 = 0.342 g.
Step 2: Convert the mass of ASA to moles:
To convert the mass of ASA to moles, you need to divide the mass by the molar mass of ASA, which is 180.16 g/mol. So, the number of moles of ASA is: 0.342 g / 180.16 g/mol = 0.001897 mol.
Step 3: Calculate the concentration of the diluted solution:
The student pipetted 3.00 mL of the solution into a 100 mL volumetric flask and diluted it to the mark with FeCl3 solution. This means that the total volume of the diluted solution is 100 mL.
To find the concentration, divide the number of moles of ASA by the volume in liters (since concentration is usually expressed in mol/L):
Concentration = moles / volume
Concentration = 0.001897 mol / 0.100 L = 0.01897 mol/L
Therefore, the concentration of the diluted solution is 0.01897 mol/L.