Education Technology

Forensics Case 9 - Killer Cup of Coffee: Using colorimetry to determine concentration of a poison

Published on 06/17/2010

Activity Overview

In this activity, students will use colorimetry to determine the concentration of a colored species in a solution and use a linear relationship to model Beer's law. They use Beer's law to determine the concentration of iron(III)thiocyanate (FeSCN2+) in an unknown solution.

Key Steps

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    With the colorimeter, students create a graph of the absorbance of known concentrations to find the concentration of FeSCN2+ in an unknown solution.

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    After the graph of the data is created, the linear regression is used to find the predicted concentration of the unknown poison.