Determining transition metal oxidation states: Recognizing bond metal-ligand types

Submitted by Brandon Quillian / Georgia Southern University on Mon, 06/27/2016 - 16:43
Description

In this in-class activity, students will determine the formal oxidation state of transition metal complexes by performing bonding type analysis of ligand−metal bonds. This in-class project is intended for those with little background in inorganic chemistry and aims to provide simple methods to calculate the formal charge of transition metals through bond-type analysis. While there are more sophisticated models already available to assign transition metal oxidation states, such as the LXZ (CBC) model, this exercise is intended for students who are coordination chemistry novices.

"Flipped Laboratory": A Discussion-based Electrochemistry Experiment for General Chemistry

Submitted by Samuel Esarey / University of Michigan on Mon, 06/27/2016 - 16:43
Description

This learning object is aimed at getting students to think critically about the data they collect in lab as they collect the data similar to how chemists typically conduct research.  They will be given a pre-lab video and a procedure prior to lab, conduct the experiment, and then upload their data to an Excel spreadsheet.  Students will then stay in their group to discuss the questions given to them on the worksheet in class with the instructor, and are allowed to continue working on them as a group up until the due date.

Student Oral Presentations of a Communication from the Primary Literature

Submitted by Carmen Works / Sonoma State University on Mon, 06/27/2016 - 16:43
Description

In the humanities it is common practice to read a piece of literature and discuss it.  This is also practiced in science and is the purpose of this exercise.  Each student is assigned a communication from the current  literature (inorganic, JACS, organometallics, J. Phys.

Coordination Compound Nomenclature Worksheet

Submitted by Elizabeth Jensen / Aquinas College on Mon, 06/27/2016 - 16:33
Description

This is a worksheet for students to complete in class to practice nomenclature of coordination compounds. It may alternatively be assigned as homework after a lesson on nomenclature. Includes examples of Ewing-Bassett system as well as Stock system.

Historical overview of Evans method

Submitted by Adam Johnson / Harvey Mudd College on Wed, 06/08/2016 - 20:08
Description

This LO grew out of my interest in understanding (deeply) the machinery behind the Evans method calculations. I did these calculations as a grad student to characterize my compounds, and I teach it in both my lecture and lab. Currently I use the metal acac synthesis lab to motivate the problem.

magnetism by Evans method

Submitted by Adam Johnson / Harvey Mudd College on Tue, 05/31/2016 - 16:27
Description

After I teach my students about magnetism and magnetic properties in coordination compounds, I spend a day showing how the data is collected and analyzed. I teach them about the Gouy balance, the Evans method of determining magnetism by NMR, and SQUID magnetometry. I also show them real data that I collected as an undergraduate or graduate student, and have them interpret and analyze it.

The only experiment that we can do locally is the Evans method, so I spend more time on this technique. We use the method during the metal acac laboratory.

Water reclamation on the ISS: “Houston, we have a problem.”

Submitted by Adam Johnson / Harvey Mudd College on Sun, 05/15/2016 - 13:57
Description

Equilibrium reactions are those that are dynamic: the reaction can shift to form more reactants or more products depending on the physical or chemical conditions present. They were discovered and described empirically, but have a thermodynamic basis in the Gibbs Energy of the reaction. A reaction at equilibrium has both reactants and products present, and the rate of formation of products is equal to the rate of formation of reactants. A common application of equilibrium is the chemistry of aqueous acids. Acid strength is measured by the pH scale.

Crystal Field Theory and Gems--Guided Inquiry

Submitted by Adam Johnson / Harvey Mudd College on Sat, 05/14/2016 - 21:42
Description

The colors of transition metal compounds are highly variable. Aqueous solutions of nickel are green, of copper are blue, and of vanadium can range from yellow to blue to green to violet. What is the origin of these colors? A simple geometrical model known as crystal field theory can be used to differentiate the 5 d orbitals in energy. When an electron in a low-lying orbital interacts with visible light, the electron can be promoted to a higher-lying orbital with the absorption of a photon. Our brains perceive this as color.

Ligand Field Correlations for Square Pyramidal Oxovanadium(III)

Submitted by Matt Whited / Carleton College on Fri, 04/22/2016 - 10:37
Description

Students work in groups to derive the ligand-field diagram for a square-pyramidal vanadium(III) oxo complex using octahedral V(III) as a starting point. The activity helps students to correlate changes in orbital energies as a function of changing ligands and geometry as well as rationalizing why certain geometries can be particularly good (or bad) for particular complexes. The activity also helps students see why oxo complexes of early metals are frequently best described as triple bonds.