Featured in PASCO’s Chemistry through Inquiry Teacher Guide

Chemistry through Inquiry Teacher Guide


Features over 25 inquiry based labs covering the fundamental concepts of lab skills, structure & properties of matter, chemical reactions and more.

Beer's Law

Lab Summary

Use a colorimeter to determine the concentration of a copper (II) sulfate solution.


Determine the concentration of a copper(II) sulfate solution using a colorimeter. Through this investigation, students:

  • Understand the difference between absorbance and transmittance of light.
  • Become aware of the effects the three variables (chemical substance, path length, and concentration) have on the absorption of light.
  • Determine the relationship between absorbance of light through a solution and the concentration of the solution (Beer’s law).


Students conduct the following procedures:

  • Dilute a copper(II) sulfate solution of known concentration to create five calibration standards.
  • Graph the absorbance of orange (610 nm) light against concentration.
  • Use linear regression to determine the line of best fit and, subsequently, determine the concentration of an unknown copper(II) sulfate solution.

Sensors / Equipment Used:

PASPORT Colorimeter Sensor


Our PASPORT Colorimeter records all 4 wavelengths simultaneously--no need to guess at wavelength to get a quality measurement.

PASPORT Sensor Extension Cable


Allows an additional two meter length extension on all PASPORT sensors.

Materials Used:

Beaker, 100-mL - 2
Test tube, 20-mm × 150-mm - 6
Test tube rack 
Volumetric pipet with bulb or a pump, 10-mL - 2
Non-abrasive cleaning tissue 
0.80 M Copper(II) sulfate - 30 mL
Unknown copper(II) sulfate (a solution less than 1.0 M) - 10 mL
Distilled (deionized) water - 30 mL

Your Bundle Options:

Option 1:

Chemistry Starter Sensor Bundle


A sensor bundle specifically designed to get you started using probeware in your chemistry lab. Also: perform 22 Lab Activities from Chemistry through Inquiry teacher guide.

Option 2:

Chemistry Standard Sensor Bundle


Contains the sensors and probes needed to perform all 17 experiments in the Advanced Chemistry Teacher Guide and all 25 labs in the Chemistry through Inquiry Guide.

Interface Required

This experiment may require software and an interface for data collection.