First year

27 Jul 2008

Polyhedral Model Kit Video Lab Manual (Jmol)

Submitted by Mike Condren, Christian Brothers University
Description: 

Some interactive Jmol models of some common crystal systems and some geological systems.

http://chemistry.beloit.edu/edetc/pmks/index.html

Prerequisites: 
Corequisites: 
Implementation Notes: 

Can show why water expands when it freezes.

Can show the cavities of zeolytes.

2 Apr 2008

Werner's Nobel Prize Address

Submitted by Maggie Geselbracht, Reed College
Evaluation Methods: 
Some or all of the discussion questions could be assigned for students to complete before or afterwards.
Evaluation Results: 
A guided discussion works well, particularly helping students translate historical terminology into modern language.
Description: 
Alfred Werner's Nobel prize address in 1913 offers a unique historical view on the development of coordination chemistry from the expert. With a bit of "translation" to modern terminology, this paper is very accessible to most students. Discussion of the address provides a useful introduction to coordination complexes including structure, isomers, and ligand substitution reactions. I find it interesting to mix in results from modern characterization techniques (for example, showing crystal structures of different hydrate isomers) while talking about how Werner might have characterized these compounds given the experimental tools of his time.
Prerequisites: 
Course Level: 
Subdiscipline: 
Related activities: 
Implementation Notes: 
I typically use this as a first exposure to coordination chemistry in a sophomore-level inorganic chemistry course. We discuss this in conjunction with a lab experiment in which students carry out classic syntheses of cobalt Werner complexes, although we have not yet covered coordination chemistry at all in lecture.
Time Required: 
50 minutes
6 Mar 2008

Smelting with Thag and Friends

Submitted by Nancy Scott Burke Williams, Scripps College, Pitzer College, Claremont McKenna College
Evaluation Methods: 

None (yet)

Evaluation Results: 

They often forget to use coefficients in their calculations, for which this is a good reminder.

Description: 

This is just a little worksheet that I use in a General Chemistry course to teach Gibbs Free Energy calculations and the idea of a coupled reaction, while foreshadowing ideas from metallurgy and electrochemistry (sacrificial reductants, entropy-driven smelting, fuels as reductants) for the end of the course when I generally address these.

Prerequisites: 
Corequisites: 
Course Level: 
Equipment needs: 

Pens and/or pencils

Implementation Notes: 

At this point, I have generally discussed Gibbs Free Energy and explained how to calculate Gibbs Free Energy, Enthalpy, and Entropy of Reactions by using tabulated values for absolute entropies and Heats and Free Energies of Formation. This gives them a little practice at it, and shows some of the pitfalls (you can only use Delta Gf when you're at 25C, if your enthalpy is negative and entropy positive, there is no temperature at which the reaction becomes non-spontaneous, etc.)

Time Required: 
ca. 25 min, depending on the amount of attendant discussion
27 Jan 2008

Nobel Prizes

Submitted by Maggie Geselbracht, Reed College
Evaluation Methods: 

I usually do not assess this in any formal way.

Evaluation Results: 

When I ask my 2nd year students to name any Nobel Prizes they know of that deal with inorganic chemistry, typically nobody can think of any Nobel Prizes, except maybe Marie Curie.

Description: 

This is a list of Nobel Prizes that in my opinion were either in Inorganic Chemistry or in an area that has impacted Inorganic Chemistry.  I pass this out to students on the first day of class when we are talking very generally about what inorganic chemistry is all about.  This could be extended into a longer discussion at this point or at a later point on one or more of the prizes.  For example, later in the semester I have them read the Nobel Prize address of Alfred Werner.  This helps to inform their lab work and introduces coordination chemistry, which we have not yet discussed in lecture.

Prerequisites: 
Topics Covered: 
Corequisites: 
Related activities: 
Time Required: 
Less than one class period
4 Jan 2008

copper ammonia complexes

Submitted by Adam R. Johnson, Harvey Mudd College
Description: 

The reaction chemistry of aqueous copper(II) ions with ammonia is commonly used in both general chemistry and inorganic chemistry texts to illustrate the equilibria of complex ions in solution.  Although the system initially seems simple, further analysis of the chemical species involved shows that it is in fact quite complicated.  First of all, ammonia is a weak base and its basic equilibrium reaction must be taken into account.  Second, although the aquated copper(II) ion is the most prevalent ion in solution before ammonia is added, this species is itself a weak acid.  Third, a series of four coordination complex equilibria are established once ammonia is added.  Finally, sparingly soluble copper(II) hydroxide precipitates as the hydroxide concentration rises due to the ammonia base equilibrium.  

Typically, when the reaction chemistry of copper(II) with ammonia is discussed, the acid-base and precipitation equilibria are ignored.  Although the mathematical description of the full system is unwieldy, it can be solved numerically using a software program such as MathCad, Mathematica or Maple.  Such a treatment provides a thorough description of the real chemical system, complete with precipitation and redissolution of the copper hydroxide precipitate.  This seemingly simple system encompasses three major classes of equilibrium chemistry commonly taught in inorganic chemistry:  acid-base, complex ion formation, and solubility.

 

much more information here: 

J. Chem. Educ. 2005, 82, 408

­

Course Level: 
Prerequisites: 
Corequisites: 
Equipment needs: 

standard glassware, buret

Subdiscipline: 
Topics Covered: 
Time Required: 
10-20 minutes
4 Jan 2008

Professional Ethics

Submitted by Lori Watson, Earlham College
Description: 

This is an assignment designed to help students begin to reflect on professional ethics of scientific practice.  I have used this in a freshman and a senior seminar after 2-3 days of discussion of what professional ethics is and how one goes about choosing a course of action in an ethical dilemma.  I use:

The Ethical Chemist : Professionalism and Ethics in Science (Educational Innovation Series) by Jeffrey Kovac
 The Chemist's Code of Conduct: http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_A...

 

Topics Covered: 
Prerequisites: 
Equipment needs: 

None

Corequisites: 
4 Jan 2008

Personal Radiation Dose

Submitted by Lori Watson, Earlham College
Evaluation Methods: 

None.<br />

Evaluation Results: 

Students love this exercise. They are quite surpised at the difference of living near a coal vs. a nuclear plant.

Description: 
I mostly use this exercise as a "see, most of your radiation does is NOT from nuclear plants."  I have used this in both General Chemistry and Inorganic Chemistry when doing a nuclear chemistry or energy production unit.
Prerequisites: 
Corequisites: 
Topics Covered: 
Equipment needs: 
None
Subdiscipline: 
Implementation Notes: 

Helps if you have some sense of the elevation you live at, and/or the elevation of places that your students came from.

Time Required: 
10 minutes
4 Jan 2008

In Lewis' Own Words

Submitted by Nancy Scott Burke Williams, Scripps College, Pitzer College, Claremont McKenna College
Evaluation Methods: 

See implementation notes. What I evaluate is the sorts of questions and answers the students generate both on their own and in the discussion.

Evaluation Results: 

I've been very impressed by the level of discussion this generates. The students love the paper for its readability, the "outdated" ideas, and the cleverness of the hypotheses put forth. They are very good at putting themselves in Lewis' position, knowing what he did, and the discussion quickly developed (this year) to a surprisingly deep discussion of the nature of scientific truth, the iterative scientific method, and the role of theory and experiment. The students "get" these models, and can see how powerful they are even though they are "wrong". I finished by emailing them Bronowski's incredibly powerful monologue on scientific knowledge: 

 

Description: 

This is G. N. Lewis' classic paper explaining his "octet rule" and the idea of bonds being represented as shared electron pairs.  It's beautifully written, and is a lot of fun for students to read.  Highlights include his description of atoms as being concentric "cubes" of eight electrons at the vertecies, philosophical discussions of the importance of letting experimental observations guide the development of theory, and the sense that students gain that Lewis developed this theory completely in the absence of an orbital or Bohr-type model of the atom.  It wonderfully captures the way in which a brilliant mind wrestled with the problems of developing a bonding theory for the periodic table.  Students understand the paper pretty easily, and are capable of picking out little "gems" on a first read of their own which they bring to a discussion.  

Prerequisites: 
Corequisites: 
Learning Goals: 

Students should be able to address the following questions:

(1) Explain Lewis' original "cube model" and his subsequent "tetrahedron model" of the atom.

(2) Why does Lewis abandon his first for his second model in this paper, even though it contradicts the prevailing theory of the day.

(3) Compare and contrast what Lewis actually proposed with the "Lewis Dot Model" which youlearned in genchem. 

(4) Please discuss the usefulness of  low-level theory which is easy to use vs. high-level theory which is hard to use, and articulate the value (or lack thereof) of doing things at a "simplistic" level.

Implementation Notes: 

I hand out this paper in advance of one class and have the students bring the answers to the questions in the handout as well at three questions of their own, which they give to another student. By the next class, they try to answer those student questions, and we use all of the questions so generated as a basis for a full class discussion.

Time Required: 
5 minutes on one day, plus one additional day for discussion (students read beforehand)
4 Jan 2008

Fun with Mercury

Submitted by Nancy Scott Burke Williams, Scripps College, Pitzer College, Claremont McKenna College
Evaluation Methods: 

If they ooh and aah, you did it right. A good demo for early in genchem, perhaps when discussing density.

Evaluation Results: 

Meh.

Description: 

Simply take a large dish, and fill it with liquid mercury.  Float things on the mercury.  Rocks, iron nails, witches, lead shot, you name it. It's best to start with the least ridiculously dense things, and build up to lead shot.

WARNING: Mercury is way bad for you, kids. Use appropriate caution.

OTHER WARNING:The mercury will amalgamate with many of these things (like lead), so that this sample of mercury will be contaminated with other metals, so this sample of mercury should be dedicated to this demo, and can be reused year after year. It should be clearly labeled with appropriate warnings about other contaminants (e.g. lead).

Subdiscipline: 
Corequisites: 
Course Level: 
Topics Covered: 
Equipment needs: 

Large recrystalization dish

Funnel

Intestinal Fortitude

Time Required: 
A few minutes
17 Nov 2007

Athletic Periodic Trends Review

Submitted by Lori Watson, Earlham College
Evaluation Methods: 

Expert: The students get all periodic trends correct, can articulate all conflicting trends and make reasoned judgements as to which dominates, appreciate subtleties (size effects larger toward the left). Can articulate correct reasoning for their orderings even in complex situations. For example, can rationalize a diagonal trend.

Proficient: Students understand the primary periodic trends in isolation. Have some difficulty with conflicting trends. Subtleties essentially absent. Can articulate correct reasoning for their orderings in simple situations and inconsistently in complex situations. For example, can rationalize horizontal and vertical trends.

Apprentice: Students can arrange atoms/ions in primary trends correctly but do not articulate correct reasoning for their orderings. For example, trends may be memorized (size goes up as you go down).

Novice: Students can not consistently arrange atoms/ions in primary trends without coaching and cannot articulate correct reasoning for their orderings. For example, may know what happens to size as you go up and down but not left to right.

Evaluation Results: 

Students generally do very well at ordering atoms according to "simple" trends (like atomic size).  Less familiar trends (polarizability, for example) or trends including ions (particularly mixed groups of atoms and ions) students seem to find more difficult.  

Description: 

­In this activity, students self-organize according to periodic trends. I print out the attached cards onto card stock (each page will contain two) and hand them out to the students (one to each). Generally, we go outside and I shout out periodic trends (i.e. size, polarizability, ionization energy, Zeff etc.) and the students run to get in line in the correct order.  I have a bell which I ding if correct, and a buzzer that I sound if incorrect. If incorrect, they have to try again. Students can "shout out" to their peers suggestions as to the ordering.  After the students are in the correct order (and sometimes when they are in the incorrect order if I see a consistent misconception in their thinking) I ask at least one student the reason for their chosen ordering. The "Instructor Notes" describe how I use this activity in General and Inorganic Chemistry and include a discussion of some common student misconceptions.

This activity typically takes about 10-15 minutes at the end of the lecture period in which we review periodic trends.  It can be easily modified for classes of different sizes by adding more atoms and ions.

Learning Goals: 

A student should be able to apply his/her knowledge of periodic trends to participate in ordering a list of atoms and ions according to a given trend and should be able to explain the reasoning behind her/his choices. 

Prerequisites: 
Topics Covered: 
Equipment needs: 

The attached atom cards printed on card stock as well as a buzzer and a bell (or two other sound making devices).

 

 

Corequisites: 
Course Level: 
Implementation Notes: 

The students really like this! Especially if they get to go outside (though running up and down the chemistry hallway is fun, too)!

Time Required: 
15 minutes

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