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If absorbance values exceed 3.0, flash persistently, or are preceded by a “>” sign, record the value as “3.0 MAX”. Place such data points on your spreadsheet graph (hand in) but DO NOT use them in your best line fit.
AbsorbanceGRAPH – BEER’S LAW (KOOL-AID FLAVOR 1); for in–lab data check only
Concentration (mg/L) GRAPH – BEER’S LAW (KOOL-AID FLAVOR 2); for in–lab data check only Absorbance
Concentration (mg/L) GRAPH –BEER’S LAW (EXTRA) Name: _________________________ Lab Instructor:___________________ POST LAB REPORT QUESTIONS (submit to instructor when mindtap report is due) I. Calculations (Show How You Calculated the Bulleted Items; (include units and the correct number of significant figures) Part A: Preparing Kool-Aid solutions • Mass of mix 1 transferred: • Stock solution concentration: • First dilution’s concentration: II. Additional Questions 1. Which wavelength choice among those available with the Vernier colorimeter would be the best choice for a Beer’s Law experiment using strawberry Kool- Aid? Why? 2. List your data and calculated concentrations for your two unknowns: Kool-Aid Flavor Std curve slope Y-intercept Unknown ID Absorbance Concentration 1: 2: 3. How does the wavelength of maximum absorbance relate to a substance’s color? 4. Do your stock solutions obey Beer’s Law, given your calibration range equations? Why or why not? 5. How did your transferred mix mass compare to the amount listed on the package label? 6. A lab pair’s Beer’s Law calibration graph 0.08 < A < 0.79 had a best-fit line of A =0.013 C – 0.023. Data was: off-scale for both the stock solution and solution #1 (10.00 mL stock diluted to 25.00 mL); solution #2 (1.00 mL stock diluted to 25.00 mL) had A = 0.85, and solution #3 (1.00 mL of solution #1 diluted to 25.00 mL) had A = 0.73. What are the concentrations of solution #3 and the stock solution?