4. Using the calibration curve below, what is the concentration of a Cu2t solution which had an absorbance of 0.450? Absorbance as a Function of Concentration of Cu2+ 0.800 0.700 0.600 0.500 0.400 0.300 0.200 0.100 0.000 0.800 0.700 0.600 0.500 0.400 0.300 0.100 0.200 0.000 [Cu2] EXPERIMENT 7 121 Absorbance

4. Using the calibration curve below, what is the concentration of a Cu2t solution which had an absorbance of 0.450? Absorbance as a Function of Concentration of Cu2+ 0.800 0.700 0.600 0.500 0.400 0.300 0.200 0.100 0.000 0.800 0.700 0.600 0.500 0.400 0.300 0.100 0.200 0.000 [Cu2] EXPERIMENT 7 121 Absorbance

Macroscale and Microscale Organic Experiments

7th Edition

ISBN:9781305577190

Author:Kenneth L. Williamson, Katherine M. Masters

Publisher:Kenneth L. Williamson, Katherine M. Masters

Chapter14: Ultraviolet Spectroscopy, Refractive Indices, And Qualitative Instrumental Organic Analysis

Section: Chapter Questions

Problem 4Q

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6. Blue Blue dye stock solution 0.293 M Absorbance at 630 nm 0.00265 Calibration curve y = 0.0833x A solution is prepared by diluting 2.79 mL of the blue dye stock solution to 25.00 mL. The measured absorbance for the prepared solution is listed in the data table. (a) What is the theoretical molar concentration? [Blue]theoretical x 10 |M (b) What is the experimental molar concentration? [Blue]experimental x 10 M (c) What is the percent error? Percent error (blue) = %
13. 0 0 0 5 The following curve was made by absorption spectrophotometry (2 = 500 nm) of standard protein solutions using the Lowry method you will perform in lab Exercise #4. If an unknown protein solution was analyzed using the same system and an absorbance value of 0.125 was measured, what was the protein concentration of the unknown? 1 Absorbance at 500 nm 0.8 0.6 0.4 0.2 y = 1.492E-03x + 3.513E-02 0 100 A. 107 μg/mL B. 83.7 μg/mL C. 71.4 μg/mL D. 60.2 µg/mL 200 300 400 500 600 Protein concentration, ug/mL
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A colored ion solution has a concentration of 0.200 M with a measured absorbance A = 0.880. Another ion solution made of the same chemicals has an absorbance A = 0.172. What is the concentration of this unknown sample solution?
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Substance P has an extinction coefficient of 72.22 mM-1cm-1 at 420nm. 2 μl of Substance P was added to 998 μl water and the Absorbance at 420nm was 0.820. Calculate the mM concentration of the original Substance P solution
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4. The total absorbance of a solution is the sum of the absorbances of all different materials present. AT = Aa + Ap + Ac .. etc. At 427 nm, the molar absorbtivity of Yellow #5 is 2.73×10°M-1-cm1. At 427 nm the molar absorptivity of Red 40 is 7.49x103 M-1.cm-1. Calculate the total absorbance of a solution in which the concentration of Yellow #5 = 2.00x10-5 M and the concentration of Red 40 = 4.80x10-5 M, when measured at 427 nm in a 1.00 cm cell.
4. A solution containing complexes of Bi (III) and thiourea has a molar absorptivity of 9.32 x 103L cm1 mol1 at 470 nm. Calculate the absorbance of a 6.24 x 105 M solution in a 1.00 cm cell. A. 58.15 x 10² B. 5.815 x 10° C. 1.494 x 10® D. 5.815 x 10-7
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