Submitted by Alycia Palmer / The Ohio State University on Mon, 07/14/2014 - 09:06
My Notes
Description

This is the second part of a two-day class discussion on molecular and inorganic spectroscopy. In this activity, upper level students learn about spectroscopic tecniques used in inorganic chemistry and then devise an experiment to follow the progress of a hypothetical reaction. The activity also prepares students for the inorganic laboratory "Linkage isomerism of nitrogen dioxide" in which infrared spectroscopy is used to monitor changes to the N-O vibrational stretch upon coordination to a metal. During class students use the primary literature to obtain experimental values that are used in the activity and later during the lab.

The first activity is described in a separated VIPEr submission, Inorganic Spectroscopy Introduced Using and Interactive PhET Sumulation (Part 1), and investigates the interaction of light (microwave, infrared, visible, ultraviolet) with small molecules, including nitrogen dioxide.

A special thank you goes to the other contributors of these activities: Julia Chamberlain, PhD; Ted Clark, PhD; and Rebecca Ricciardo, PhD

Attachment Size
Student Version of Slides 113.75 KB
Student Worksheet 68.58 KB
Learning Goals

Students should be able to:

  • Describe, in general, how each different region of the electromagnetic spectrum influences molecules.
  • Explain how FT-IR can be used to monitor the coordination modes of NO2 on a cobalt complex.
  • Interpret data in a literature article and determine how the results in the literature relate to a laboratory experiment.
  • Design a series of spectroscopic experiments to identify intermediates in an inorganic synthetic pathway.
Equipment needs

Parts of the presentation were designed to be used with a stylus during class discussion portions. Drawing and writing examples are included on the hidden slides as an example (available in the "faculty only" file). These slides can be unhidden and adapted for use without a stylus as well.

Implementation Notes

Facilitator notes are included as comments on all documents and can be viewed by selecting "Show Comments" under the review tab in Power Point or "Show all markup" under the review tab in Word.

This activity was implemented in a lecture setting with a class of 16 students. The group work was implemented during the 1-hour class that meets weekly and accompanies the 3-hour inorganic laboratory. Students were instructed before class to bring a copy of the article referenced in their laboratory (Penland, Infrared Absorption Spectra of Inorganic Coordination Complexes) and their completed worksheet from the previous week's activity, Inorganic Spectroscopy Introduced Using and Interactive PhET Sumulation (Part 1).

 

Time Required
One 55-minute class period

Evaluation

Evaluation Methods

Students' worksheets were collected at the end of the class period to analyze student responses.

Evaluation Results

Students worked in small groups on Parts 1 and 2, completing these sections quickly and accurately. The third section was more difficult for students, as they were required to search for data in a research paper. This part was more manageable when done as a class, where students worked together to complete the table which was copied on the front chalkboard. This method was useful for the instructor to correct mixed up numbers and to help students understand what each number represents. Students were very confused about how coordination to a metal changes the frequency of a vibration, so much time was spent in clarifying this concept.

Parts 4 and 5 were completed in small groups, and students did not ask many questions while completing these tasks. However, responses on the worksheet for part 5 were not very detailed and could have benefited from more discussion, either with the instructor or as a brainstorming session with involvement from the whole class.

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