Periodic trends

14 Jul 2014

The Structure and Color of Alums

Submitted by Erica Gunn, Simmons College
Evaluation Methods: 

This LO has not yet been tested. 

Students could be asked to summarize:

a. the relevance of periodic trends to the color of alum crystals

b. why potassium alum is colorless and chrome alum is colored

c. how the crystal field splitting varies with periodic trends, and how this is (or is not) related to the color of the alums

d. rank the predicted field splitting values for a different series of metal impurities or different set of isomorphous crystals

e. explain why crystal field theory is limited in its ability to predict color in the alum crystals (only after a more advanced discussion of ligand field theory - see instructor notes)

 

This data could be collected in several different ways:

a. Class discussion or review in a future lecture period

b. Quiz, exam, or final exam question

c. Minute paper or clicker question

 

 

Evaluation Results: 

This LO  has not yet been assessed.

Description: 

This is an in-class assignment designed to help students integrate their understanding of periodic trends and materials properties. Using the color of alum crystals as an example of octahedral coordination chemistry, students use their knowledge of electronic structure and periodic trends to predict which of the isomorphous alum crystals will be colored, and to qualtitatively rank the degree of crystal field splitting in a family of alum crystals.

Learning Goals: 

In answering these questions, a student will:

- Apply knowledge of electron configurations to predict which metal ions will produce color.

- Use the spectrochemical series to determine whether the metal ions in an alum crystal will be high or low spin

- Compare field splitting for different alum compositions based on periodic trends

 

Corequisites: 
Prerequisites: 
Topics Covered: 
Course Level: 
Implementation Notes: 

This worksheet was developed for a second-year descriptive inorganic chemistry class. Students have been introduced to periodic trends, electron configurations for transition metals, crystal structure and site symmetry, and are beginning a discussion of crystal field theory. They should also have been exposed to the spectrochemical series and ligand field splitting. This worksheet is used as a way of integrating knowledge across several chapters and several weeks of the semester, in preparation for a more advanced discussion of color in pigments and gemstones. After a brief introduction, students will work in small groups during class time to answer the worksheet questions. The questions follow closely with content in the textbook (Descriptive Inorganic Chemistry Raynor-Canham, Overton 6th ed.), and so should be mostly a review and opportunity for students to apply their understanding to a concrete problem.

Time Required: 
1 hour
7 Jul 2014

Dissecting Catalysts for Artificial Photosynthesis

Submitted by Anne Bentley, Lewis & Clark College
Additional Authors: 
Evaluation Methods: 

Anne’s student led a 20-minute class discussion of this article in the spring of 2014.  The other students in the class were asked to post two questions about the article to moodle before the class meeting, but they were not asked to complete the literature discussion questions due to assignment overload at the end of the semester.

Evaluation Results: 

Students’ questions varied from the very specific to the very general.  One wanted to know what the parameter “tau” referred to, and another was confused about the concept of overpotential.  Many students weren’t sure why making carbon monoxide would be a good idea, as they see it as poisonous.  One student wanted to know if these catalysts could ever be used in ambient conditions.  Students were curious to know more about the catalytic mechanism.

Description: 

Anne asked the students in her junior/senior inorganic course to develop their own literature discussion learning objects and lead the rest of the class in a discussion of their article.  Each student chose one article from a list of suggestions provided.  Student Hayley Johnston chose this article describing a Mn-containing catalyst for carbon dioxide reduction (Jonathan M. Smieja, Matthew D. Sampson, Kyle A. Grice, Eric E. Benson, Jesse D. Froehlich, and Clifford P. Kubiak, “Manganese as a Substitute for Rhenium in CO2 Reduction Catalysts: The Importance of Acids” Inorganic Chemistry 2013, 52, 2484-2491. DOI: 10.1021/ic302391u).  The article describes the development of a Mn-based homogeneous catalyst for electrocatalytic CO2 reduction.  Hayley met with Anne for an hour to discuss the article, then generated a list of questions drawn from the article's content.  Using Hayley’s original set of questions as a starting point, Anne and Kyle developed this literature discussion, which is suitable for use in inorganic chemistry courses.

Corequisites: 
Course Level: 
Learning Goals: 

After reading and discussing this paper, a student will be able to:

  • Describe the value of CO2 reduction catalysts
  • Outline the structure of the catalyst and identify the path electrons take throughout the catalytic cycle
  • Compare and contrast the Mn-based and Re-based catalysts in terms of their CO2 reduction efficiency
Implementation Notes: 

The learning object we've developed contains fifteen questions that cover most of the article's content in great depth.  It's likely too long for an individual assignment, depending on the students' backgrounds.  We encourage instructors to pick and choose from among the questions. 

Before discussing this article, students should be familiar with the concepts of renewable fuels/artificial photosynthesis and maybe also the Keeling curve demonstrating the sharp increase in atmospheric carbon dioxide over the past two hundred years.

Students may not know that CO, carbon monoxide, is very useful. They will likely be most familiar with its dangers, not its importance in industrial chemistry. Instructors could discuss the uses of CO: synthesis of methanol (nearly all industrial methanol comes from CO), synthesis of acetic acid (nearly all of the acetic acid comes from CO and methanol), hydroformylation, and Fischer-Tropsch chemistry (which could be used to make gasoline/diesel – South Africa has used this technology for some time).

A discussion of cyclic voltammetry would also be useful, including discussing the role of ferrocene as an internal reference. We have referenced the “five slides about” LO Cyclic Voltammetry created by Prof. Chip Nataro as a related activity.

In terms of placing this manuscript in context, previous studies included rhenium complexes, which work without added proton sources but are much improved in the presence of proton sources. The seminal work on rhenium complexes was performed by Jean-Marie Lehn (of supramolecular Nobel Prize fame) in the 1980s.

A comprehensive review of the history of these Re and Mn complexes from their discovery up to early 2013 can be found in “Chapter Five  – Recent Studies of Rhenium and Manganese Bipyridine Carbonyl Catalysts for the Electrochemical Reduction of CO2” Kyle A. Grice and Clifford P. Kubiak Advances in Inorganic Chemistry201466, 163-188  (see web resources below).

Several more recent papers have also been published on the Re and Mn systems from the Kubiak group and other groups since early 2013, including mechanistic studies of the Re and Mn systems using a variety of methods. A forward search of the Mn manuscript by Smieja et al. can be used to find these articles.

For more detailed information about IR-SEC, see this reference and references therein: Charles W. Machan, Matthew D. Sampson, Steven A. Chabolla, Tram Dang, and Clifford P. Kubiak Organometallics, 2014, ASAP  (see web resources below).

 

 

Time Required: 
45 minutes
1 Jul 2014
Evaluation Methods: 

Students were evaluated on how completely they answered the pre-class reading questions.  

In-class discussion questions were collected at the end of the class period.  For these, students worked in groups of 2 or 3.

Evaluation Results: 

Most of the students grasped the major concepts by the end of the class, though there was a lot of initial confusion as to how to make sense of all the structural data in the paper.

The biggest hurdle students had to overcome was shifting their thinking from absolute terms (e.g., sodium is hard) to relative terms (e.g., sodium is harder than potassium).  Once they did this, the rest of the activity becomes very simple.

Description: 

In this literature discussion, students are asked to read an article describing a series of uranyl halide compounds that contain an alkali counterion that interacts with one or more of the uranium's ligand atoms.  This paper stands out as a great example of the binding preferences of acids and bases, and can be explained very well using simple HSAB concepts.  Also notable in this paper is the fact that the authors claim that HSAB concepts explain their results very well in the introduction, and then only bring it up again almost as an afterthought in the short discussion section at the end of the paper.

Corequisites: 
Prerequisites: 
Learning Goals: 

A student should be able to rank Lewis acid and bases in terms of relative hardness

A student should be able to interpret X-ray crystallographic structural data and identify structural motifs

A student should be able to explain the affinity that atoms have for one another in terms of HSAB theory

 

Implementation Notes: 

This activity is fairly straightforward, and my students needed little help working through the discussion questions.  For most students, this was the first time they had seen molecules represented as thermal ellipsoids, so they had a little trouble identifying the atoms inside molecules, but everyone got it by the end of the class.

Time Required: 
One 50 minute class period
24 Jan 2014

Student choice literature-based take home exam question

Submitted by Hilary Eppley, DePauw University
Evaluation Methods: 

This question was 30 points on a 100 pt take home exam (the year I did this, there was also a 100 point in class exam as well).   I've included the title page of the take home exam as well as this question.   

The grading scale allowed most of the points for the student chosen course content to highlight.   Of the 30 points, 10 focus on chemical information skills, 20 on summarizing the article and analyzing it using concepts from the class.   

Evaluation Results: 

I gave back a number of the exams before I was able to tally, but of the ones I had remaining: 

60% got full credit on the part a (those who missed neglected to include a summary) 

100% got full credit on part b

60% got full credit on part c (those who missed searched by formula rather than connectivity or provided an insufficient explanation of what they searched on 

100% got full credit on part d

On part e, answers varied widely from 7/17 to 15/17, with an average of 12/17 or a 70%.  

In some cases they lost points for just repeating things verbatim from the paper without explaining them to show they understood the concepts.   The main reason for loss of points however was just a lack of effort at picking apart the paper for parts that were relevant to the course content.   

They were able to successfully apply things such as electron counting and mechanism identification in a catalytic cycle, point groups, descriptions of sigma and pi bonding in ligands.   

 

Description: 

During my junior/senior level inorganic course, we did several guided literature discussions over the course of the semester where the students read papers and answered a series of questions based on them (some from this site!).  As part of my take home final exam, I gave the students an open choice literature analysis question where they had the chance to integrate topics from the semester into their interpretation of a recent paper of their own choice from Inorganic Chemistry, this time with limited guidance.  I also included a number of questions that required them to make use of various literature search tools to show that they had mastered those skills.   I gave them a list of topics that they could incorporate, but based on the poor quality of the responses I received, I encourage you to be more specific in your instructions.  I'd love to see some new versions!      

Corequisites: 
Course Level: 
Prerequisites: 
Learning Goals: 
Students will
  • choose a recent paper that interests them from Inorganic Chemistry
  • summarize why a particular paper is important to the field of inorganic chemistry
  • use literature search tools including Web of Science, Cambridge Structural Database, and SciFinder Scholar to find information aobut cited references, structurally similar compounds, and the authors of the paper
  • integrate ideas such as bonding models, symmetry, spectroscopy structural data, and chemical reactivity from class into a detailed analysis of aspects of the paper

The instructor will

  • get up to date on new literature for possible new literature discussions
  • get a chance to stretch his/her own intellectual muscles on some papers perhaps outside of his/her area of expertise
Implementation Notes: 

The students were given the take home exam about 1 week before it was due (but that was during the final exam period).   The format of the chemical information questions were similar to things they did earlier in the class, however the analysis of the paper was much more open ended, giving them the freedom to choose a paper that interested them and to presumably focus on concepts from the class that they felt comfortable with.   I gave them a date range from April 1 - April 30, 2012 for their paper because those were the most recent issues at the time.  If you use this LO, you will probably want to change those dates to more recent ones.   

Time Required: 
at least an hour, possibly more depending on the student
27 Jun 2013

QSAR and Inorganic Chemistry

Submitted by Vanessa McCaffrey, Albion College
Description: 

This presentation provides a short introduction to Quantitative Structure-Activity Relationships and its use in Inorganic Chemistry. A brief introduction to Linear-Free Energy Relationships and the Hammett Equation is given, followed by three examples of how QSARs have been used in inorganic chemistry. 

Corequisites: 
Learning Goals: 
  • Define QSAR
  • Describe the Hammett equation, including definitions of each variable
  • Give examples of how QSAR can be used to predict properties of inorganic systems
Implementation Notes: 

This "5 slides" would fit well at the beginning of a junior or senior level inorganic class. It is designed to help students draw parallels between organic and inorganic systems and the ways that chemists can evaluate the properties of different systems. 

27 Jun 2013
Evaluation Methods: 

We have currently not evaluated this method.  We believe that this method could be generalized to examine any literature article.  As we test this LO, we will post our assessment data.

The related LO, Tuning the band gap of CZT(S,Se) nanocrystals by anion substitution, contains discussion questions on the article that can be used for additional evaluation.  We have also developed questions that we believe would use this concept map specifically.  We would enjoy comments on how these two related LOs are being used and assessing whether concept mapping helps students understand literature articles.

Description: 

Concept maps are a visual way to organize and represent information. In this literature discussion, we introduce a novel technique for teaching literature analysis to students where concept maps are used for establishing relationships between the key ideas, theories, procedures, and methods of a proposed literature article. Using the article “Compositionally Tunable Cu2ZnSn(S1-xSex)4 Nanocrystals: Probing the Effect of Se-Inclusion in Mixed Chalcogenide Thin Films” (Riha, S.C.; Parkinson, B.A.; Prieto, A.L. J. Am. Chem. Soc., 2011, 133, 15272-15275.) as a case study, students are asked to identify the key terminology related to the synthesis, properties, analysis, and application of semiconductor nanoparticles and are tasked to develop a concept map interrelating important conceptual ideas and results.

 

Learning Goals: 

LG1:  Identify key words that describe aspects synthesis, applications, properties, and analysis

LG2:  Create a concept map by identifying how the key words are related

Corequisites: 
Prerequisites: 
Implementation Notes: 

Supplies Needed:

- packs of sticky notes

- 3’x5’ poster paper or large sticky note pads

- markers

 

Before class

Students will be asked to read the paper before class and write down some key words and terms. There is an attached student handout to facilitate this process; this document briefly describes concept maps to students and gives three larger categories for students to begin grouping their key terms.

(The in-class activity may be implemented in a variety of ways to meet your classroom needs. Here we suggest a model conducive for small group work.)

In class

Begin with a class discussion about the terms or ideas that were found while reading the paper. As a group you might want to place these ideas into one of the three categories: synthesis, analysis, or properties. (Perhaps come up with several more at this point.) Students may then break into smaller groups and focus on one category (if you have a large class, you may choose to have multiple groups for each category). Provide each group with sticky notes and instruct them to write one term on each sticky note (a dry-erase board or large poster paper can also be used in place of sticky notes). They should begin constructing a concept map for this category. Ask students to consider the relationship between any concepts that are connected by lines and perhaps to write a short phrase that describes this relationship.

When these groups have developed the section of the concept map in some detail, bring the class back together to construct the larger concept map integrating the individual maps prepared by each group. Begin to think about the inter-connection of concepts within different categories.

There is a related learning object with discussion questions related to this paper, which may be used as a problem set for homework, guidance for discussion, or a wrap-up activity.

**NOTE** The goal of this learning object is to create a concept map for this article. One example of a concept map for this article has been provided in the instructors information. However, it must be noted that the map generated by your class will not necessarily be identical to the one that has been provided. It is expected that there will be variations between the different concept maps generated.

26 Jun 2013

Literature summary through student presentation - free choice of topic.

Submitted by Cameron Gren, University of North Alabama
Evaluation Methods: 

I typically weight this assignment as one-half of an exam, i.e. 50 points when exams are worth 100 points each. The question should be worth a portion, perhaps 10 points with the remaining points coming from the presentation. Another option could be, if it would be appropriate for your class, to dedicate a few points to students preparing questions of other presenters. For large classes, they need not all be asked, but simply handed in to you prior to each presentation. then YOU could ask a few of them. As far as a rubric for the presentations, this could vary greatly. I typically count off for things like incorrect information, extremely vague descriptions, or very weak question answering. Specific deductions may vary. Other evaluation options could include student evaluations on each other's presentations, giving a post-presentation quiz (covering all presentations), or possibly including questions on the final exam over the presentations.

Evaluation Results: 

I generally give good grades for this assignment if I can tell the students put in an appropriate amount of work. Students tend to enjoy this assignment (more so after completing it, of course), as they can truly take ownership of their work. They seem to have a good sense of accomplishment after tackling a difficult journal article and breaking it down so they can understand it.

Description: 

(1) Student choses and reads a journal article of his/her choice that is related to a topic we have discussed during the semester. (i.e. atomic structure, MO theory, group theory, solid state structure, band theory, coordination chemistry, organometallics, catalysis). Suggested journals include, but are not limited to JACS, Inorg. Chem., Organometallics, Angew. Chem., JOMC, Chem. Comm.)

(2) Student answers the following questions regarding their chosen article:

    (a) Describe, in 1 or 2 sentences the goal of this work. 

    (b) Define the primary topic(s) from our course that relate to this work. 

    (c) Do you feel the authors achieved their goal? Why or why not?

    (d) What questions remained about the work?

(3) Student prepares a brief (~15 min) PowerPoint (or equivalent program) presentation describing the article. The question set should aid the student in developing the presentation.

(4) Students are encouraged to ask questions following each other student’s presentation.

Course Level: 
Learning Goals: 

• Students will improve their overall reading comprehension with regards to chemical literature.

• Students will be able to identify the relationship between current chemical literature and key concepts in inorganic chemistry.

• Students will improve their ability to present chemical research in a concise but detailed manner.

• Students will become critical observers of other’s presentations, being able to formulate and ask insightful questions.

Implementation Notes: 

I have this assignment due the last few days of the semester. It may be valuable for the students to see the professor summarize an article in this manner first, although I do not do this. It may be valuable to make the journal articles available to the other students prior to the presentations. This might help them formulate insightful questions for the presenters.

Time Required: 
I usually assign this at the beginning of the semester, although ~ 2 weeks might be sufficient prep time. In-class time is about 20 mins per student.
25 Jun 2013
Evaluation Methods: 

Students write a formal report which is evaluated with respect to whether each learning goal is achieved.

Evaluation Results: 

Earlier versions of this project have been assigned to approximately 30 students in three senior-level inorganic chemistry courses over a six year period, with substantial revisions made each time. Students were generally able to reproduce the literature results successfully and to gauge which method is expected to be most reliable for first-principles calculations of redox potentials. There was some variability in students’ choice of fullerenes which appropriately span the range of interest. Some students were able to make fairly sophisticated suggestions for future work. 

Description: 

In this project students are asked to reproduce published calculations of molecular orbital energies of a series of derivatized fullerenes and correlate them with published reduction and oxidation potentials obtained from cyclic voltammetry. The particular subset of the derivatives to be studied are chosen by the student and this choice is part of the learning activity. The students then carry out additional calculations using other theoretical models to see whether they improve the correlation between computed and experimental properties. Interpretation of the trends and suggestions for additional work are discussed in a formal report. 

Corequisites: 
Learning Goals: 

After completing this project, students will be able to

  • Summarize the use of cyclic voltammetry to measure redox potentials;
  • Use computer software to build and visualize molecular models of derivatives of buckminsterfullerene;
  • Carry out density functional theory and semiempirical calculations of buckminsterfullerenes;
  • Discuss how derivatization affects the energies of the frontier orbitals;
  • Implement different theoretical models and correctly choose the one which best correlates with the experimental data;
  • Discuss which computational method is likely to be most useful in the prediction of redox potentials from first principles; and
  • Write a formal report describing their findings.
Course Level: 
Equipment needs: 

Modern computer workstation with 6+ GB RAM; molecular structure building and visualization software; quantum mechanics software. Spartan 8 has all of the capabilities required for this project.

 

Implementation Notes: 

The models are built and the calculations are carried out at our institution using Spartan 10, but Gaussian, GAMESS, Q-Chem, NW-Chem or other programs with similar capabilities could be used instead. 

Time Required: 
Students are asked to complete this as an independent project, although the work could be done as a group in one or two laboratory periods if a computer classroom is available.
31 May 2013

Lithium Diazenide Surprise!

Submitted by Maggie Geselbracht, Reed College
Evaluation Methods: 

During conference, I gave students direct feedback on the MO diagrams and cartoons of MO surfaces their groups had drawn on the board.  As this conference was scheduled the day before a problem set was due, this feedback was helpful to students in gaining confidence drawing MO diagrams of diatomics. 

I collected the discussion questions and graded these on a 10 point scale, 1.5 points for question 1, 0.5 point for question 3, 3 points for question 7, 1 point for questions 2, 4, 5, and 6, and 1 point for effort.

Evaluation Results: 

Out of the 15 students that turned in written answers, 6 (40%) earned 9-10 points, 5 students (33%) earned 6.5-7 points, another 2 students (13%) earned 5-5.5 points, and 2 students (13%) earned < 5 points.  On the MO diagrams, I told them I did not care if they invoked sp­-mixing or not in their diagrams, but that they needed to be consistent with their choice.  In other words, if the 3 sg energy level was shown above the 1 πu energy levels in their diagram, then I expected to see evidence of sp­-mixing in their molecular orbital surface cartoons.  About half of the students chose to use sp­-mixing in their diagrams, but most of them did not show evidence of sp­-mixing in the molecular orbital surfaces.  Others that chose to invoke sp­-mixing did not shift the MO energy levels correctly; the common mistake was elevating the 2 su* energy level above the 1 πu energy levels rather than the 3 sg energy level.  Nearly all students that have read this paper find it approachable and understand the major conclusions and how these were reached after the discussion.

 

Description: 

Students in a sophomore-level inorganic chemistry course were asked to read the paper “High-Pressure Synthesis and Characterization of the Alkali Diazenide Li2N2” (Angew. Chem. Int. Ed. 2012, 51, 1873-1875. DOI: 10.1002/anie.201108252) in preparation for a class discussion.  For many students, this was a first exposure to reading the primary literature. 

In this paper, the authors describe the surprising stability of lithium diazenide, Li2N2.  In contrast with the increasing stability of peroxides and superoxides with the heavier alkali metals, the first alkali metal diazenide that was isolated was not the rubidium or cesium salt but rather the lithium salt (hence the surprise)!  The black, metallic-looking Li2N2 was synthesized at high pressure and high temperature by the decomposition of lithium azide, LiN3.  The crystal structure of Li2N2 was determined by Rietveld refinement of powder X-ray diffraction data and relevant bond distances were compared to diazene, H2N2, and the alkaline earth diazenides, CaN2, SrN2, and BaN2.  The authors also report evidence from infrared spectroscopy of nitrogen-nitrogen bonds in Li2N2.   Electronic band structure calculations suggest metallic behavior for Li2N2 and antibonding characteristics for the conduction electrons consistent with the molecular orbital description of the isolated diazenide ion.

Course Level: 
Prerequisites: 
Corequisites: 
Learning Goals: 

After reading and discussing this paper, a student will be able to:

  • Articulate the underlying problem and motivations driving the research presented in the paper.
  • Explain the collection of experimental data that lead to figures and tables presented in the paper.
  • Describe the important conclusions of the paper and the evidence presented by the authors to support these conclusions.
  • Gain confidence reading a paper from the primary literature in inorganic chemistry.
  • Describe periodic trends in the descriptive chemistry observed for the alkali metals with oxygen and for the alkali metals with nitrogen.
  • Interpret images of a unit cell to deduce stoichiometry and notable coordination features of an extended structure.
  • Draw the molecular orbital diagram of a homonuclear diatomic species and use the MO diagram to predict the bond order and magnetic properties of the diazenide ion.
Implementation Notes: 

Students in a sophomore-level inorganic chemistry course read the paper "High-Pressure Synthesis and Characterization of the Alkali Diazenide Li2N2" prior to a class discussion, held during a conference session.  A link to the pdf file was posted to the course Moodle, and students were asked to complete the short list of discussion questions (attached below as a Word document) prior to coming to conference.  I also used the Jmol resource embedded in a course Moodle page to display the unit cell of the Li2N2 structure (the pdb file that I used as the input for Jmol is attached below.) On the Moodle page with the Jmol structure, I told students, “Sorry, I don't know how to make Jmol draw the boundaries of the unit cell!  To guide your eye, there are lithium atoms (in lavendar) at all 8 corners of the unit cell.”  This Jmol model was intended to help students answer questions 4 and 5 in the attached list of questions in addition to Figure 2 from the paper.

I used this learning object during the past two years at different times during my course.  In Spring 2012, the paper was assigned in week 4 of the semester, after covering periodic trends in atomic properties, ionic structures, unit cells, stoichiometries of extended structures, basic X-ray powder diffraction, and Lewis structures.  In Spring 2013, the paper was assigned in week 9 of the semester, after MO theory of diatomics was also covered in addition to the previous topics.  The attached discussion questions were from the Spring 2013 version.

During conference, we used the discussion questions as a guide to walk through the paper.  I explained to students how to access the Supporting Information for a paper and the varying utility of this information, depending on the article.  In this case, the Supporting Information is quite helpful, and we talked through key figures and tables in both the paper and in the Supporting Information.  We also discussed the synthesis, and I answered some questions on the characterization methods, explaining briefly what Rietveld refinement is and how the results in Table 1 and Figure 1 are correlated.  For more information on the Rietveld refinement method, see the Web Resource on Powder Diffraction Crystallography Instructional Materials.  Finally, we took the last 10 minutes of conference, and I made all the students get up and in small groups, draw the MO diagram and molecular orbital surfaces for (N2)2– on the white boards around the room.  I circulated and made comments and corrections to each group on their MO diagrams.  

I also used this paper for one student as part of our Junior Qualifying Exam in Inorganic Chemistry.  In this format, the student has 3 days to read the paper and learn about it before taking a 30 minute oral exam, which takes the form of a question-and-answer based discussion of the paper.  For the Junior Qual, we spent most of the time discussing the diffraction analysis of the material, molecular orbital theory of the diazenide ion, and a brief discussion of the properties of lithium diazenide.

Finally, although I have not done so yet, I intend to use this paper in my Advanced Inorganic Chemistry course where we cover the electronic band structure of extended solids in more detail. Our discussions in Advanced I-chem are based on Roald Hoffmann’s book, Solids and Surfaces: A Chemist’s View of Bonding in Extended Structures.  The details of the Li2N2 electronic band structure calculations provided in the Supporting Information for this paper are an excellent illustration of many of the key concepts presented in Hoffmann’s book.

Time Required: 
50 minutes
21 Apr 2013

General Chemistry Electronic Study Aids

Submitted by David Kreller, Georgia Southern University
Description: 

At this website students can access interactive game-like learning resources that cover a wide range of topics in general chemistry.  These learning activities, which are in the form of flash cards, quizzes and matching games, will help student learn and review/drill important general chemistry topics. 

Course Level: 
Subdiscipline: 
Prerequisites: 
Corequisites: 

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