Determination of Aspirin in Tablets Chemistry 112L, Section 001 September 17, 2014 A.Research Question What is the relationship between the concentration of aspirin and the absorbency of the solution? B.Observations & Results Tables Table 1. Molar Absorptivity of Aspirin: Concentration vs. Absorbance Aspirin (g/mL)Absorbance (au) 0.00 g/mL0.000 au 0.0000100 g/mL0.129 au 0.0000200 g/mL0.219 au 0.0000400 g/mL0.361 au 0.0000600 g/mL0.513 au 0.0000800 g/mL0.773 au 0.000100 g/mL1.169 au Table 2. Aspirin Tablet Data BrandAdvertised% aspirin(from bottle)Tabletmass (g)Abs of analyzedtablet solutionMass ofaspirin pertablet (g)% aspirin per tablet (from analysis) Bayer82.9 %0.392 g0.806 au0.177 g45.2 % Kroger86.7 %0.375 g0.368 au0.388 g103% Graphs

0000000 0 0.2 0.4 0.6 0.8 1 1.2 1.4 f(x) = 10390.39x R² = 0.99 Molar Absorptivity of Aspirin: Absorbance vs. Concentration Concentration (g/mL) Absorbance (au) Calculations Aspirin concentration calculations are written on the attached notebook paper. Advertised % of aspirin per tablet: Bayer: 0.325 g / 0.392 g = 0.8290816… = 0.829 *100 = 82.9 % aspirin by mass Kroger: 0.325 g / 0.375 g = 0.8666666… = 0.867 * 100 = 86.7 % aspirin by mass Mass of aspirin per tablet, and percent of aspirin per tablet are calculated in the analysis.