Question

the determination of aspirin in commercial preparations experment explain why the FeCl3-KCl-HCl solution was ased as a reference solution. suggest a procedure you could follow to determine whether it was necessary to use this solution as a reference or whether distilled water would have been just as satifactory

Answer 1

In the determination of aspirin in commercial preparations experiment FeCl₃-KCl-HCl solution was used as a reference solution.

To determine the absorption of the aspirin, we used solution of aspirin + FeCl₃-KCl-HCl. But we only want to know the absorption of aspirin alone. FeCl₃-KCl-HCl solution is used as blank solution. There is no need to know the absorption of FeCl₃-KCl-HCl. Use FeCl_3-KCl-HCl as the blank solution to zero the absorbance reading.

For this purpose we need 400 mg of aspirin, 1.0 M NaOH Solution and Iron (III) Chloride solution buffered to a pH of 1.6 with HCl-KCl buffer. Use micro pipet to add 300 μL ASA stock in 10.0 mL volumetric flask. Fill the flask to the mark with acidified FeCl₃solution.The solution will have a medium dark violet color. Measure and record the absorbance at 530 nm. So it was necessary to use FeCl₃-KCl-HCl solution as a reference