Chem 2 WS 98
Post-lab: Colorimetry

Name:___________________

Section:__________________

Convert the following absorbance data into percent transmittance (1 pt.)
(a) 0.25





(b) 1.2






2. Calculate the concentration of an unknown using the following data (1 pt.)

standard concentration = 10 ppm
drops of standard in color match = 6
drops of unknown in color match = 8








3. The absorbance of a 7.5 x 10-4 M solution of a compound is 0.68 at wavelength 595 nm in a 1 cm cell, calculate the extinction coefficient. (2 pts.)