Introduction to Colorimetry
This 4-wavelength Colorimeter measures the amount of light transmitted through a sample at a user-selectable wavelength in order to determine the concentration of a solution. Features such as automatic sensor identification and one-step calibration make this sensor easy to use. The colorimeter can be used for colored solutions and provides an alternative to the more expensive UV-Vis instrument. Unlike the UV-Vis instrument, the colorimeter measures within the visible range of the electromagnetic spectrum.
In this laboratory experiment, your students will use the Vernier colorimeter to analyze a series of pre-made cobalt standards and a pre-made sample. Using the absorbance values, they will generate a calibration curve and solve for the unknown concentration.
PRODUCT INFO
This U-PIK will include enough materials for six student groups. Suggested group size is 3-4 students. The U-PIK will include the following:
- 6 colorimeters
- 6 LabQuest 2 interfaces
- 7 sets of cobalt standards (varying concentrations)
- 7 Unknown cobalt samples
- Set of plastic cuvettes
- 6 boxes of Kimwipes
You will be required to provide your own water (distilled or deionized) needed for the experiment. Tap water is not recommended, however, it will have a minimal impact on the laboratory experiment.
WHEN TO INTEGRATE?
The colorimeter can be easily used to support the concept of the visible spectrum. All solutions will be colored and analyzed in the visible portion of the electromagnetic spectrum.
Due to the mathematical concepts presented (slope and linear regression line), the laboratory should be introduced in a high school science classroom. It should be suitable for any science course discussing the electromagnetic spectrum and visible light.
Time: One laboratory period.
Student Level:
INTERMEDIATE (Grades 9-12)
Colorimeter User Manual
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