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.
B.
C.
D.
100
100 M cm
100 M-1 cm-1
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
B. 20.4 µg/ml
C. 150 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