Dilutions and Spectral Properties of Solutions

Carmen Nezat, Eastern Washington University

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The purpose of this week's lab is to
- prepare calibration standards
- use a UV-Vis spectrometer to determine the spectral peaks for several dye solutions, and create a calibration curve
- calculate how much of each single-element standard solution is needed to make a multi-element stock solution

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upper level environmental geochemistry course

Skills and concepts that students must have mastered

unit conversions, density of solutions, calculating concentrations of solutions created from diluting a stock solution (e.g., C1V1=C2V2), calibration curve

How the activity is situated in the course

This lab activity is assigned a few weeks into the course but before geochemical analysis using an ICP-OES.


Content/concepts goals for this activity

The content goals of this activity include:
-calibration standards and calibration curves
-spectral peaks of different solutions with different analytes
-serial dilutions

Higher order thinking skills goals for this activity

High order thinking skills goals include:
-develop and apply calibration curves in order to determine the unknown concentration of an analyte in a sample
-evaluate the correctness of a calibration curve
-reinforce students' ability to accurately calculate concentrations of solutions made from more concentrated solutions

Other skills goals for this activity

Other goals include:
-operating analytical equipment
-accurately pipetting solutions to make dilutions
-working in small groups

Description and Teaching Materials

Materials needed:
file "Dilutions and Spectral Properties of Solutions"

Assignment for "Dilutions and Spectral Properties of Solutions" Assignment (Microsoft Word 2007 (.docx) 33kB Apr29 13)

Teaching Notes and Tips


The total number of points for this assignment is 100. The number of points assigned to each question is listed next to the question in the handout.

References and Resources