Dilutions and Spectral Properties of Solutions
Summary
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
- 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
Context
Audience
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.
Goals
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
-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
-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
-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"
Teaching Notes and Tips
Assessment
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.