A sample of ibuprofen (102.9 mg) was dissolved completely in…

A sample of ibuprofen (102.9 mg) was dissolved completely in 50 mL ethanol. One mL of this solution was diluted to 200 mL with water. The absorbance of this solution at 221 nm was found to be 0.453 in a 1 cm cell. Calculate the percentage purity of the sample, given that the specific absorbance of ibuprofen at 223 nm in water is 449.  (5 marks)