Food Dye Calorimetry Lab Report

This experiment sought to determine how much food dye was in each color of PowerAde, this was done with the use of a spectrometer to measure absorbency and concentration of the dyes in the drinks. Three colors of dyes were tested in the spectrometer to identify the maximum absorbency wavelength of each. Figure one shows the max absorbency and concentration for each color of dye. For each of the dyes the light transmitted was the color of the food dye that was seen however the absorbed color was its complimentary color. For example yellow was the color transmitted however blue was the color absorbed, red was the color transmitted and green was the color absorbed and blue was the color transmitted and orange was the color absorbed. The second

The calibration curve shows the absorbency with varying concentrations of a blue dye water mixture. Beers law (A= e b c) suggests that by connecting the points on the graph, a straight line should occur because absorbance is proportional to concentration1.The equation at the top of the graph was used to calculate the amount of dye in the actual PowerAde solution. The absorbency of the blue PowerAde was taken from the spectrometer as 0.56. By putting 0.56 into the formula as y, determining the concentration was as of simple as solving for x. By looking back at figure 2 it was determined that a concentration of 5.1x10-6 moles falls between test tube 4 (40% concentration and 3.9x10-6 moles) and test tube 3 (60% concentration of the dye and 5.9x10-6 moles) therefore we can conclude it is in the middle of these two concentrations approximately 51% concentration. This shows that approximately 51% of blue PowerAde is dye and the other 49% is water and other substances. The results also suggest that because the mixture was transmitted as a blue color, the absorbed color would have been orange, it's complimentary color. It can be concluded that the max wavelength absorbency corresponds to a particular color that is transmitted from a substance the color we see, however the color that is absorbed is always its complimentary