**Background:**

This laboratory introduces students to absorption
spectrophotometry and the Beer-Lambert Law. After performing a
background correction of the spectrometer using a solvent blank,
the student measures the absorbance of an analyte solution over a
wide wavelength range to determine the wavelength of maximum
absorption. Then the absorbances of standard solutions of known
concentration are measured, along with the absorbance of an
unknown. The student develops a working curve for the standards,
obtains the equation for the linear fit, and calculates the
concentration of the unknown and answers questions about the
observations.

**Learning Objectives:**

- Introduction to Beer's Law and the relevant equation
parameters.
- Illustrate how to background correct a spectrophotometer,
adjust its wavelength of study, and measure absorbances.
- Illustrate how to develop a working Beer's Law plot and use it
to calculate concentration values.
- Be able to discuss the relationship between absorption
wavelength and the color of a solution.