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Online Chemistry Labs | Learning Objectives

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.

 Absorbance LO

Learning Objectives:

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