Lab 6 Outline

Background Information

• https://openlab.citytech.cuny.edu/bio1101coursehub/lessons/lab/spectrophotometry/
• https://openlab.citytech.cuny.edu/bio1101coursehub/lessons/lab/beers-law/
• https://openlab.citytech.cuny.edu/bio1101coursehub/lessons/lab/the-equation-of-a-line/

Activities

• https://openlab.citytech.cuny.edu/bio1101coursehub/lessons/lab/lab-6-activities/

General Outline

Please review the directions for using the Spectrophotometers with Angelika or Nina. The Exploring Beers Law Virtual lab is also useful to provide students prior to entering the lab to understand how the equipment works when coming to class.

Please view this video at 1.25X to assess if you would like to use the new equipment. You may ask Angelika Brekman or Nina Cheprasova to try the equipment prior to the class if there is time. You may also find me and I will run through the use of these. If you use the Vernier Spectrovis equipment, it is best to let the students set up the experiments while you attach the USB to the SpectroVis Plus and the LabQuest2 units.

1. Review the electromagnetic spectrum and visible light properties
2. Review Beer-Lambert and the relationship between concentration and absorption
3. Review the theory of spectrophotometers using the simulation (Simulation/Modeling)
4. Review dependent/independent variables
5. Perform the dilutions and make measurements (Quantitative Reasoning)
6. Go over graphing, slope-intercept form of the equation of a line, and use
   http://phet.colorado.edu/sims/curve-fitting/curve-fitting_en.html
   1. Use the equation of the line to estimate the concentrations of the two unknowns that you choose to provide the student groups (Quantitative Reasoning)
   2. You may opt out of graphing the data by hand and have the students create plots with software for homework and provide the unknown concentrations
      1. Students often have difficulty using Excel or spreadsheets but it can be done at
         home
      2. You may opt to have them use plot.ly (https://chart-studio.plotly.com/create/#/)to create the plots and send them to you by
         email
         1. The tutorial for this can be viewed at https://youtu.be/jeRMxXvbI7g
         2. The advantage of this software is that it is simplified for only plotting
         3. Students can log-in for free using their Facebook, Twitter, Google or Github credentials

Curricular Notes

These exercises emphasize NSF Vision & Change Core Competency

1. Simulation/Modeling: Beer’s law simulation, spectrophotometer simulation
2. Quantitative Reasoning: using the equation of a line

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