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Quiz 1. Beer’s law is A = ε bc . An analyte at a concentration of 5.0 x 10 -3 M gives an absorbance of 0.50 at a specific wavelength and a cell path length of 1.00 cm. What is the molar absorptivity ? Show your work. A. 100 B. 100 M cm C. 100 M -1 cm -1 D. 100 M cm -1
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Quiz 1. Beer’s law is A = εbc. An analyte at a concentration of 5.0 x 10-3 M gives an absorbance of 0.50 at a specific wavelength and a cell path length of 1.00 cm. What is the molar absorptivity? Show your work. A. 100 B. 100 M cm C. 100 M-1 cm-1 D. 100 M cm-1 2. The percent transmittance (%T) is the percentage of light: A. absorbed by the sample. B. not absorbed by the sample. C. reflected by the sample. D. emitted by the sample.
Quiz • 3. You are analyzing compound ‘X’ using absorbance spectroscopy. A standard containing 50.0 µg/mL of ‘X’ gives a % transmittance of 15.9. The blank % transmittance is 97.2. What is the concentration (µg/mL) of a sample of ‘X’ that gives a % transmittance of 47.8? • A = 2.00-log(%T). Show your work. • A. 128 µg/ml C. 150 µg/ml • B. 20.4 µg/ml D. 19.6 µg/ml • 4. Fluorescence involves the: • A. the absorption and then emission of a photon. • B. the absorption and then emission of an electron. • C. the absorption of a photon and then dissipation of heat. • D. none of the above
