Food Dye Proposal 2 v4.9

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Feb 20, 2024

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Chemical Thinking Food Dye Group Proposal 2 v4.9 | 1 Food Dye Summary and Group Proposal 2 Your name: Brock Dale Your email: brockdale@arizona.edu Your lab partner’s name(s): Adilson Inacio Your lab partner’s email(s): aginacio@arizona.edu Your lab instructor’s name: Paige Sandoval Your lab section: 002C All workmust be veryneat and organized . If you need to collect your thoughts, pleaseusea separatesheet of paper. Proposals area groupeffort . Pleasesubmit the completed document as a PDF to the FoodDyeGroupProposal 2 D2L DropBoxbeforethe scheduled end of lab. Alwayscheckto confirmthecorrectdocument/filehasimportedtothecorrectlabD2LDropboxfolder– noexcuses. Submissiontoanincorrect Dropboxfolder will be subject toa 1-point penalty. If you submit an unintended document, or need to update a submission, you can always resubmit so long as you are not past the deadline . If yousubmit thewrongdocument andfail to realizethisuntil after thedeadline, a resubmissioncannot beaccepted. So pleasebe careful andalwaysdoublecheck! 1. Session 2 Goals (1 pt) . In complete, well-written sentences, summarize in your own words the goals for this second session of the Food Dye Project (not the entire Project – just the second session of the Project ). The goals for the second session of the food dye project is to carry out the proposal we created in group proposal #1, as well as to calculate the mass of each food dye in our assigned drink. Then create a new and improved group proposal (Group proposal #2) on how to determine the molar concentration of each dye in the unknown drink. 2. Implementing Group Proposal 1: Parallel Dilution Sets (4 pts) . Using the Parallel Dilution Set Infographic to guide you, complete Table 3 below for one (1) FD&C dye in your group’s assigned drink, specifying the dye by FD&C color + number . Do the same for the second FD&C dye employing Table 4 . Note, in each dilution set, one parallel dilution set member is the undiluted stock solution , hence V diluent and V D must be 0.0 μ L for this member. In the space below the tables, present in a very organized manner, one example concentration calculation for one dilution set member that is not the undiluted stock, clearly stating symbolically the equation(s) used and then substituting in actual values. Include correct units throughout. Table 3. Parallel Dilution Set for FD&C Food Dye Blue #1 Volume of Stock ( V S ) Volume of Diluent ( V diluent ) Volume of Dilution ( V D ) Concentration 3000 𝜇 L 0 𝜇 L 3000 𝜇 L 6.96E-6 M 2325 𝜇 L 675 𝜇 L 3000 𝜇 L 5.394E-6 M 1650 𝜇 L 1350 𝜇 L 3000 𝜇 L 3.132E-6 M 975 𝜇 L 2025 𝜇 L 3000 𝜇 L 2.262E-6 M 300 𝜇 L 2700 𝜇 L 3000 𝜇 L 6.96E-7 M Table 4. Parallel Dilution Set for FD&C Food Dye Yellow #5 Volume of Stock ( V S ) Volume of Diluent ( V diluent ) Volume of Dilution ( V D ) Concentration 3000 𝜇 L 0 𝜇 L 3000 𝜇 L 2.99E-5 M 2325 𝜇 L 675 𝜇 L 3000 𝜇 L 2.32E-5 M 1650 𝜇 L 1350 𝜇 L 3000 𝜇 L 1.64E-5 M 975 𝜇 L 2025 𝜇 L 3000 𝜇 L 9.72E-6 M 300 𝜇 L 2700 𝜇 L 3000 𝜇 L 2.99E-6 M Cs*Vs / V D = C D (Concentration) CHEM 151 FDP2 v4.9 5-5-23

Chemical Thinking Food Dye Group Proposal 2 v4.9 | 2 (2.99*E-5 M/L * 3E-4 L) / 0.003 L = 2.99E-6 M 3. Implementing Group Proposal 1: Calibration Curves (6 pts) . In EXCEL prepare calibration curves (absorbance versus concentration plots) for each FD&C food dye identified in your assigned drink. Use the Beer’s Law Calibration Curve Infographic to guide you. Carefully reproduce (draw) or paste-in each A vs. C plot (calibration curve) giving the linear trend-line equation with R 2 value (from EXCEL) for each plot. Remember to title and label your graphs correctly. Clearly state the λ max for the dyes and the inferred molar absorptivity values. Include correct units throughout . 0.00E+00 5.00E-06 1.00E-05 1.50E-05 2.00E-05 2.50E-05 3.00E-05 3.50E-05 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 f(x) = 24562.61 x − 0.03 R² = 1 Absorbance vs. Concentration Calibration Curve (Yellow dye #5 λmax 422nm) Concentration (M) Absorbacne 0.00E+00 1.00E-06 2.00E-06 3.00E-06 4.00E-06 5.00E-06 6.00E-06 7.00E-06 8.00E-06 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 f(x) = 112832.67 x + 0.04 R² = 0.98 Absorbance vs. Concentration Calibration Curve (Blue dye #1 λmax 624nm) Concentration (M) Absorbance CHEM 151 FDP2 v4.9 5-5-23

Chemical Thinking Food Dye Group Proposal 2 v4.9 | 3 4. Molar Concentration of the FD&C Food Dyes (4 pts) . Present the complete calculations to determine the molar concentration of each FD&C dye in your assigned drink (unknown) using only the Group Proposal 1 results reported above. To receive credit, the presentation must be very well-organized and highly legible. First state the equation(s) being used symbolically, then substitute in values and show the result(s). Include correct units throughout . The absorption is determined by the λ max peaks of the unknown drink and the absorbance at those peaks. The λ max at 418nm (yellow dye) of the drink the absorbance is 0.589. The λ max at 624 nm (blue dye) of the drink the absorbance is 0.222. The slope values are taken from the trend lines of each dye’s calibration curves. Yellow dye trend line slope = 24563 Blue dye trend line slope = 112833 C = A/(Slope) C (yellow dye) = 0.589/24563 = 2.398E-6 (M) C (Blue dye #1) = 0.222/112833 = 1.968E-6 (M) CHEM 151 FDP2 v4.9 5-5-23

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Chemical Thinking Food Dye Group Proposal 2 v4.9 | 4 5. Group Proposal 2 (5 pts) . Given your Group Proposal 1 experience, propose a complete plan (procedure) with modifications/corrections to improve the quantitation of the FD&C food dyes in your assigned drink. Note, to be “complete” a new (or repeated for a second time) parallel dilution set and calibration curve for each dye is required. Be sure to include an accurate, legible, well-organized sequence of proposed calculations (equations) for determining the mass (in grams) of each FD&C food dye present per 500 mL serving of assigned drink . Please NUMBER your procedural steps . Procedural Steps 1) Get 10 – 15 ml of each dye in your unknown drink, the unknown liquid, and nano pure water in separate vials. 2) Calibrate the Spectrometer using a “blank” (~ 3000 𝜇 L Nanopure water) cuvette 3) Fill a cuvette with 3000 𝜇 L of the unknown drink, place into the Spectrometer and keep the graph to use it later. 4) Refer to the Parallel Dilution Set Infographic and set up a parallel dilution set for one of the known dyes in the drink. 5) Place the first 3000 𝜇 L cuvette into the spectrometer, record the absorption value at the λmax. 6) Place the recorded values into a table. 7) Repeat this step for each of the cuvettes created from the dilution set 8) Calculate the molar concentration of the diluted dye in each cuvette created in the dilution set, using the equation CD = Cs*Vs/VD 9) Record the concentrations in a table 10) Repeat steps 4-9 for the second dye in the drink 11) Using the calculated concentrations and absorption values of each dye, create a Calibration Curve for each dye using the Beer’s Law Calibration Curve Infographic 12) Using excel determine the slope of the trend line of your plot chart for both charts 13) Record the slope values for later 14) Using the λmax’s of the unknown drink and the slopes of your dyes calibration curves use the equation, C = A/(Slope), to determine the molar concentration of each dye in the unknown drink. 15) Record the values produced by the equation in step 14 16) To determine the mass in grams of each dye in 500ml of the known drink we take the values produced by step 14 and divide them by 2 to determine the mass in grams of each dye in the drink. 17) Finally, Record the mass of dye in the drink. CHEM 151 FDP2 v4.9 5-5-23