Analysis of Iron in Liquid Vitamin Supplements
unit involves students in colorimetric analysis of liquid
vitamin supplements. Phenanthroline is used as a sensitive
indicator for iron, and students first establish a calibration
curve for the iron-phenanthroline complex. Then they use
this calibration curve to determine the concentration of
iron in vitamin supplements. These activities were designed
for use by high school chemistry students and may be most
appropriate for honors or AP classes.
unit involves students in analysis of “real world”
samples and gives them a role in development of experimental
procedures. The lab activities were designed to be safe
and feasible for high school students. This unit was written
for use with Vernier LabPro hardware and the accompanying
LoggerPro software, but it is readily adaptable to use with
Spectronic 20 or other spectrophotometers.
The unit was
developed by Catherine Oertel, a graduate student in chemistry
at Cornell University and Mary Kay Hickey, a chemistry teacher
at Dryden High School. The lab was piloted in March 2004
with four sections of honors chemistry students taught by
Ms. Hickey and by Tim Kirkpatrick, also at Dryden High School.
1: Building a Calibration Curve
2: Determining Iron Concentration