Cameron KahnMuditha DiasExperiment 7-Postlab9 April 2014Experiment 7: UV-Vis Absorption Spectroscopy of Dyes and Caffeine in BeveragesData:Blank for caffeineAbsorbance 0.0664Sample (analyte) Wavelength (nm)Absorbance Concentration (M)Absorptivity (M-1cm-1)Blue standard 595.0474 0.976036 5.045E-06 175832.7056Red standard 505.0134 0.918359 4.029E-05 20457.40879Blue Gatorade 635.0546 0.201167 6.507E-07 175832.7056Red Gatorade 500.0078 0.754319 3.220E-05 20457.40879Caffeine standard 625.057 0.095704 1.03E-03 28.45Caffeine drink 430.0182 0.082526 5.668E-04 28.45Koolaid Blue 630.0593 0.453058 2.082E-06 175832.7056Koolaid Red 505.0134 0.617031 2.556E-05 20457.40879****the blank must be subtracted from the absorbance to calculate concentrationCalculations:***2mL of red dye was diluted to 100mL***2mL of blue dye was diluted to 500mL***Caffeine was diluted to 5mLA=ɛ ×b × cConcentration of blue and red standards:Blue:1mg1 mL×1 mol792.86 g×2 mL500 mL=5.045e-6 MRed:1mg1 mL×1 mol496.43 g×2 mL100 mL=4.029e-5 MKahn 1BlankWavelength (nm)Absorbance595.0473633 0.088926509505.0133972 0.094130643635.0545654 0.086760983500.007843 0.095645539625.0570068 0.087645605430.018219 0.114484869630.0592651 0.086956121Absorptivity of blue and red standards:Blue:AB ×C=ɛ .976036−.088965.045e-6=175832.7056 M-1cm-1Red:AB ×C=ɛ .918358−.094134.029e-5=20457.40879 M-1cm-1Concentration of blue and red Gatorade:Blue:Aɛ× b=c .201167−.08676175832.7056=6.507e-7 MRed:Aɛ× b=c .754319−0.0956520457.40879=3.220e-5 MConcentration of blue and red Kool-Aid:Blue:Aɛ× b=c 0.453058−0.086956175832.7056=2.082e-6 MRed:Aɛ× b=c 0.617031−0.09413020457.40879=2.446e-5 MConcentration of Caffeine standard:1mg1 mL×1 mol194.19 g×1 mL5 mL=1.03e-3 MAbsorptivity of standard:Ab× c=ɛ .082526−.066428.45=5.668e-4 M-1cm-11d) No we did not completely separate the dyes for red and blue because the wavelength of the highest absorbance for the standards did not match the wavelengths of the highest absorbance forthe samples (for both red and blue dyes). If we completely separated the red and blue dyes, the wavelength at the highest absorbance for both the standard and the sample would be the same.1e) Your measurements would change because you would have another dye in the sample being tested for absorbance along with the dye that you actually want to test for absorbance. So there would be an interference from the other unwanted dye which would cause a shift of highest absorbance to another wavelength.2c) the extinction coefficient for caffeine is 8750M-1cm-1 at 270nm wavelength. I found this valuefrom chacha.com. The question asked to calculate the %error in a SINGLE extinction coefficienttherefore I did not calculate the %error for the other two extinction coefficients I used for the blue and red dyes. However, it is a similar process. Also since this was in part 2 of the write up I assumed you wanted the %error of the caffeine extinction coefficient since we dealt with caffeinein part 2 of the lab.%error∈caffiene extinction coefficien t =|Actual−theoretical||Theoretical|×100=28.45−87508750×100=99.67 %2e) from google, I obtained a value of 39mg for the caffeine content of Coke a cola. Kahn 239 mg×1 g1000 mg×1 mol194.16 g×1 mol1 L=2.01e-4 Mtheoretical5.668e-4−2.01e-42.01e-4×100=181.99 %From my calculation, something went wrong. I was unsure as to what to use for the theoretical which could be my mistake. Working with the caffeine standard concentration listed in my table (1.03e-3M) I get a %error of 44.97% which seems more reasonable.Kahn