Red 40 Lab
Determining Red 40 Concentrations Using Absorption with Beer’s Law
Introduction
I like color and enjoyed learning about wavelengths and the spectrum of light, so I considered incorporating something related to that into my Internal Assessment. We also had just used concentrations in our Group 4 Project, so when I found an experiment that dealt with both of these I thought it was a great idea. This experiment is not completely original; the basic concept has been used multiple times. It uses Beer’s Law:
· A is light absorbance
· is “molar absorptivity with units of L mol-1 cm-1”
· l is the length of the cuvette in centimeters
· c is the concentration of the solution in mol L-1
The relationship between absorbance and concentration …show more content…
I had to determine, using moles of red 40 (which had a molar mass of 496.42 g/mol) and the desired starting concentration of 0.0008 mol/, how many grams of red 40 I would need. It came out to 0.0397 grams (g). Therefore, I first weighed out 0.0397 g of red 40 on the milligram scale. Next, I carefully shook out the 0.0397 g of Red 40 into a 100 volumetric flask and added diluted water to the flask until the meniscus was at the 100 mark. Then I placed the cap on the flask and put it upside down and right-side up, mixing it completely. I also had to complete the calculations for the next concentrations using =; I did this for serial dilutions of .0008 mol/, .0006 mol/, .0004 mol/, .0002 mol/, and .0001 mol/ concentrations. How many of current concentration necessary for the next desired …show more content…
However, a more complex way of investigating this further would be to attempt to determine how much more harmful higher concentrations of red dye 40 would be; for example, does the 0.000129 difference between Black Raspberry Sparkling Ice and Red Powerade make a difference in how much the health is affected, or is that difference negligible? There is as of yet no specific health standard for red 40 that I could find. It could be ethically controversial to test this further process but it is nonetheless an interesting prospect to consider.
References
· "Beer's Law - Theoretical Principles." Teaching.shu.ac. N.p., n.d. Web. 11 Mar. 2017.
· Kristen Fischer. "Is Red Dye 40 Toxic?" Healthline. Ed. Peggy Pletcher. N.p., 2 Apr. 2015. Web. 11 Mar.
Introduction
I like color and enjoyed learning about wavelengths and the spectrum of light, so I considered incorporating something related to that into my Internal Assessment. We also had just used concentrations in our Group 4 Project, so when I found an experiment that dealt with both of these I thought it was a great idea. This experiment is not completely original; the basic concept has been used multiple times. It uses Beer’s Law:
· A is light absorbance
· is “molar absorptivity with units of L mol-1 cm-1”
· l is the length of the cuvette in centimeters
· c is the concentration of the solution in mol L-1
The relationship between absorbance and concentration …show more content…
I had to determine, using moles of red 40 (which had a molar mass of 496.42 g/mol) and the desired starting concentration of 0.0008 mol/, how many grams of red 40 I would need. It came out to 0.0397 grams (g). Therefore, I first weighed out 0.0397 g of red 40 on the milligram scale. Next, I carefully shook out the 0.0397 g of Red 40 into a 100 volumetric flask and added diluted water to the flask until the meniscus was at the 100 mark. Then I placed the cap on the flask and put it upside down and right-side up, mixing it completely. I also had to complete the calculations for the next concentrations using =; I did this for serial dilutions of .0008 mol/, .0006 mol/, .0004 mol/, .0002 mol/, and .0001 mol/ concentrations. How many of current concentration necessary for the next desired …show more content…
However, a more complex way of investigating this further would be to attempt to determine how much more harmful higher concentrations of red dye 40 would be; for example, does the 0.000129 difference between Black Raspberry Sparkling Ice and Red Powerade make a difference in how much the health is affected, or is that difference negligible? There is as of yet no specific health standard for red 40 that I could find. It could be ethically controversial to test this further process but it is nonetheless an interesting prospect to consider.
References
· "Beer's Law - Theoretical Principles." Teaching.shu.ac. N.p., n.d. Web. 11 Mar. 2017.
· Kristen Fischer. "Is Red Dye 40 Toxic?" Healthline. Ed. Peggy Pletcher. N.p., 2 Apr. 2015. Web. 11 Mar.