A common task in chemistry is the determination
of concentration of unknown compounds. The Beer−
Lambert law, also commonly referred to as Beer’s law, enables
the quantitation of the concentration of an absorbing analyte
in solution. Results from experiments using solutions of blue
food dye, lemon−lime sports drink, and iron(III) chloride
demonstrated that absorbance versus concentration data are
linear for data collected using digital cameras and camera phones. The key to obtaining reliable data is collecting a single image of
samples, standards, and blanks arranged in front of a uniform light source, such as a light box or a computer screen. The approach
provides a facile method for performing colorimetric analysis in a wide range of settings, from the high school chemistry
laboratory, in the field, and the research laboratory.
KEYWORDS: High School/Introductory Chemistry, First-Year Undergraduate/General, Analytical Chemistry: Laboratory Instruction,
Physical Chemistry, Hands-On Learning/Manipulatives, Dyes/Pigments, UV−Vis Spectroscopy