Lab 6 Caitlin Cournoyer - Discovering the concentration of 8 Blue-1 Dye solutions using Beer\u2019s Law Purpose The purpose of this lab is to collect

# Lab 6 Caitlin Cournoyer - Discovering the...

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Discovering the concentration of 8 Blue-1 Dye solutions using Beer’s Law Purpose The purpose of this lab is to collect data to determine the molarity of an artificial dye in a sports drink. First we will calculate the stock solution (A-H) using the known molarity. We can use this to then predict our absorbance using Beer’s Law. Now the lab will need to be performed by making different solutions and diluting it with known molarity. Now using a spectrometer which is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, we will find the concentration of the various Blue-1 Dye solutions. We will also be putting the stock and pure water samples in the spectrometer to find their %T values. To find our absorbance and transmittance we will need to make a calibration graph to compare the absorbance to transmittance. Using the linear relationship of both the transmittance and absorbance, we can find the slope and use in our next calculations. From this we can know the concentrations of all 8 unknown Blue-1 Dye solutions. Some limitations may be with the spectrometer itself. The main disadvantage of using a UV-VIS spectrometer is the time it takes to prepare to use one. With UV-VIS spectrometers, setup is key. You must clear the area of any outside light, electronic noise, or other outside contaminants that could interfere with the spectrometer's reading. Background 1.What would be an optimum wavelength for measuring the absorbance versus concentrationof a series of FD&C Blue 1 dye solutions? Explain your answer in the context of Figure 4
For figure 6. We can see the absorption spectrum for Blue 1 FD&C Dye we can see the wavelength peaks around 600-640 because around the peak it has a higher absorbance. 2.To construct a calibration curve, a series of known concentration standards is prepared. Using the estimated concentration of the FD&C Blue 1 stock solution, determine the concentration of each of the following dilutions. Hint: M1V1= M2V2Show all calculations for each dilution.Dye Stock Solution (A)BCDEFGHConcentration (micromolar,μM)7.0μM5.6μM4.2μM2.8μM2.1μM1.4μM.7μM0μMWater (mL)024678910Stock Solution108643210
G: 1 x 7/ 10= .7 μM H: 0 x 7/ 10= 0 μM