Submitted by Peter Craig / McDaniel College on Mon, 05/11/2026 - 17:32
Additional Authors
J. Katana Ngala / McDaniel College
Katrina R. Wiens / McDaniel College
My Notes
Categories
Prerequisites
No Prerequisites
Corequisites
General Chemistry
Course Level
First year
Second year
Topics Covered
Bonding models: Discrete molecules
Chemical literature
Communication skills
Coordination chemistry
Electronic spectroscopy
Laboratory course information
Molecular structure
Physical methods / analytical techniques
Synthesis and reactivity
Visualization
Subdiscipline
Coordination Chemistry
Spectroscopy and Structural Methods
Description

This research-based laboratory series investigates the stoichiometry of metal ion complexes of the Schiff-base ligand salicylaldehyde benzoyl hydrazone (SBH) in both the solid and solution states using gravimetric analysis and UV-VIS spectroscopy.

Attachment Size
26-06-30 Research-based Laboratory Project Instructions.docx 742.71 KB
Learning Goals

After completing this project, students will have the following laboratory skills:

  • Dropwise addition of reagents
  • Vacuum filtration
  • Analytical balance use
  • Conducting condensation reactions
  • Synthesis of metal complexes
  • Preparation of solutions of specified concentrations
  • UV-VIS spectrophotometer use
  • Use of a graduated pipette
  • Making dilutions

 

After undertaking this project, giving a group oral presentation, and writing the individual final written formal lab report, students will understand:

  • How percent yield evaluates solid state stoichiometry options (gravimetric analysis)
  • How to use LoggerPro and/or Excel for plotting and fitting data
  • How to determine binding solution stoichiometry from absorbance data (Job’s Plot)
  • The relationship between absorbance and observed color
  • How to interpret and extract data from UV-Vis spectra, including identifying λmax, determining absorbance values, and relating spectral features to concentration and electronic transitions.
Equipment needs

Fume hood, standard glassware, analytical balance, magnetic stirrer/hotplate, glass and plastic pipettes, Büchner vacuum filtration apparatus, Vernier Go Direct® SpectroVis® Plus spectrophotometer (or equivalent), plastic cuvettes, and Vernier LoggerPro and Microsoft Excel software (or equivalent) on a computer connected to the spectrometer.

Related activities
Job's Method - The Covid-19 Version
Implementation Notes

This activity was used in the second half of general chemistry II laboratory to introduce students to research. It is a multiweek activity. We ran four sections of lab of up to 20 students each, with students in pairs or groups of three being assigned a specific metal ion SBH ligand combination to work with. We envision that it could also be used in a sophomore level inorganic or analytical chemistry course too.

Time Required
We used 7 x 3-hour lab sessions for this project. This could be shorter if students had more experience and/or had more resources available. See page one of the file “26-06-30 Research-based Laboratory Project Instructions.docx” for more on this topic.
Evaluation
Evaluation Methods

Evaluation is based on a group oral presentation and an individual final written report. Guidelines, common mistakes to avoid, and rubrics are detailed in the file “26-06-30 Research-based Laboratory Project Instructions.docx”.

Assessment of this research-based laboratory series is through a survey distributed to students. This is available as a faculty only file.
 

Evaluation Results

Please see the faculty only files for the assessment survey instrument and the initial round of results.

Creative Commons License
Attribution, Non-Commercial, Share Alike CC BY-NC-SA