A "Bayer brand of aspirin was dissolved in some sodium hydroxide and transferred to a 100.0 ml volumetric flask and diluted to the mark with distilled water. A 3.1ml aliquot of this solution was transferred to a second 100.0 ml volumetric flask and diluted to the mark with iron (Il) chloride solution. The concentration of the iron (II) salicylate complex was found to be 0.046mM. What was the original concentration of A.S.A (aspirin) in the original solution, in mM?
I wonder if you made a typo. According to the information I have it is FeCl3 (not FeCl2) that forms a complex with ASA which is [Fe(C6H4OCOO)]+.. In any event; however, whether FeCl2 or FeCl3 the complex is a 1:1 ratio of Fe to ASA.
0.046 mM in the final 100 mL. So the first 100 mL volumetric flask has 0.046 mM x (100 mL/3.1 mL) = ? mM in the first flask (original solution of ASA). Since the ratio is 1 mol Fe to 1 mol ASA. that is the concn of ASA.
@DrBob222 You're right. My apologies. A "Bayer brand of aspirin was dissolved in some sodium hydroxide and transferred to a 100.0 ml volumetric flask and diluted to the mark with distilled water. A 2.2 ml aliquot of this solution was transferred to a second 100.0 ml volumetric flask and diluted to the mark with iron (IlI) chloride solution. The concentration of the iron (III) salicylate complex was found to be 0.048mM. What was the original concentration of A.S.A (aspirin) in the original solution, in mM?
To find the original concentration of ASA (aspirin) in the original solution, you need to use the concept of dilution and stoichiometry.
Let's break down the given information to solve the problem step by step:
1. The Bayer brand of aspirin is dissolved in sodium hydroxide and transferred to a 100.0 ml volumetric flask.
2. The solution is diluted to the mark with distilled water. This means that the final volume of the solution in the flask is 100.0 ml.
Now, let's calculate the concentration of the solution in the 100.0 ml volumetric flask:
Concentration (in mM) = moles/volume (in L)
The volume of the solution in the flask is 100.0 ml, which is equivalent to 0.100 L.
So, the concentration of the solution in the 100.0 ml volumetric flask is:
Concentration (in mM) = moles/0.100 L
Now, we need to find the moles of the iron (II) salicylate complex in the 3.1 ml aliquot transferred to the second 100.0 ml volumetric flask.
3.1 ml is equivalent to 0.0031 L.
The concentration of the iron (II) salicylate complex in the second 100.0 ml volumetric flask is given as 0.046 mM.
So, the moles of the iron (II) salicylate complex in the 3.1 ml aliquot are:
Moles = concentration x volume (in L)
Moles = 0.046 mM x 0.0031 L
Now, we need to consider the stoichiometry of the reaction between ASA and iron (II) chloride to calculate the moles of ASA. Let's assume the stoichiometric ratio is 1:1 (1 mole of ASA reacts with 1 mole of iron (II) salicylate complex).
Since the moles of ASA are equal to the moles of the iron (II) salicylate complex, the moles of ASA in the 3.1 ml aliquot are:
Moles of ASA = 0.046 mM x 0.0031 L
Finally, we can calculate the original concentration of ASA in the original solution.
The original solution was diluted to the mark with distilled water in a 100.0 ml volumetric flask. So, the dilution factor for the ASA is:
Dilution factor = volume transferred/total volume in flask
Dilution factor = 3.1 ml/100.0 ml
Now, multiply the dilution factor by the moles of ASA in the 3.1 ml aliquot to get the moles of ASA in the original solution:
Moles of ASA in original solution = Dilution factor x Moles of ASA in 3.1 ml aliquot
Finally, calculate the original concentration of ASA:
Original concentration of ASA (in mM) = Moles of ASA in original solution/total volume in flask (in L)
By following these steps, you should be able to calculate the original concentration of ASA (aspirin) in the original solution in mM.