# Spectrophotometric Analysis of Aspirin lab report.docx -...

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Thanh Nguyen Chemistry II Lab: Spectrophotometric Analysis of Aspirin Table B: Mass of pure aspirin: .160 g Moles of aspirin: .160 g aspirin 1 mol 180.2 gaspirin = 8.88 x10 -4 mol aspirin Concentration of aspirin in stock solution, M: 8.88x10 -4 mol /0.1 L = 8.88x10 -3 M Beer’s law plot: 5.00E-051.00E-041.50E-042.00E-042.50E-043.00E-043.50E-044.00E-044.50E-045.00E-04 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.44 0.38 0.32 0.23 0.12 f(x) = 896 x + 0.06 R² = 0.98 Beer's law plot for Aspirin Concentration, M Absorbance
Sample calculations: For sample A-E, Concentration is determined by the equation M 1 V 1 = M 2 V 2 Solution A: (0.500 mL)(8.88 x 10 -3 M) = (10.0 mL)( M 2 ) M 2 for A = 4.44 x 10 -4 M, same goes for solution B through E For the unknown solution’s concentration, I use the trend feature in excel on the beer’s law plot, I can determine the concentration of the unknown when the absorbance of it is 0.408.