Solutions : Beer's Law
Explore the relationship of the absorbance of light through a solution and the concentration of the solution. Use the relationship to find the concentration of a solution.
Lab Summary
In this activity, students will make known concentrations of copper(II) nitrate solution. They will use a colorimeter to measure the absorbance of a specific color (wavelength) of light through the known concentrations in order to establish a "standard curve". They will determine the relationship of the absorbance of light to the concentration of the solution and use this relationship to estimate the concentration of an unknown solution of copper(II) nitrate.
Downloads
- Download Free Lab (PDF, 532 KB) (529 KB, .pdf)
(student version)
Method
Use a Colorimeter to determine the concentration of one or more unknown solutions by comparison to a standard Beer’s Law absorption plot.
Here's What You Need
U.S. Educator prices shown.
Probeware
PASPORT Colorimeter Sensor (PS-2121) - $119
Our PASPORT Colorimeter records all 4 wavelengths simultaneously--no need to guess at wavelength to get a quality measurement.
Xplorer GLX (PS-2002) - $349
The Xplorer GLX is a data collection, graphing, and analysis tool designed for science students and educators.
Other Materials
Beaker, 100-mL
- Label Pipette with bulb, 10 mL
- Stirring rod
- Test tube, large
- Test tube rack
- Tissue
- 0.25 M copper(II) nitrate, Cu(NO3)2
- Water, distilled
