Computer Simulations and Tutorials
for General Chemistry
at University of Missouri-Rolla
Gary L. Bertrand, Professor of Chemistry
Abstract
About the Course
Introduction
Appraisal of Individual Students
- Remediation and Review
Interactive Lecture Aids/Simulated
Demonstrations
Simulations in the General Chemistry
Laboratory
The Future
Color Coding of Text
Blue/Purple:Links
to Web Materials
Red: Web
Materials Requiring Plug-In
http://www.umr.edu/~gbert/tutorials.html
Notes on Installing
the Windows Plug-in
Green: Materials
for Downloading
Notes on Downloading
ftp://www.chem.umr.edu/bertrand
Macintosh: CCSim.sea.hqx, OmoMac.sea.hqx
Windows: CCSim.zip, OmoWin.zip
These may be decompressed with various programs,
but I recommend Aladdin Expander at
http://www.aladdinsys.com/expander/
Abstract
Computer Simulations have been used in Chemistry
courses at UMR since the early 80's. These began with an interactive simulation
of the Iodine Clock reaction, which was used as a demonstration in a lecture
room with 30 students grouped around the 13" monitor of an Apple IIe computer.
While the students at that time were somewhat distracted by the technology,
the educational impact was obvious. My assessment of that impact assigned
equal weight to the effects of visualization and interactivity, and these
have been the cornerstones of my software development and use.
Simulations and interactive software have
been developed for Appraisal of Individual Students/Review and Remediation,
Interactive Lecture Aids/Simulated Demonstrations, and as Simulations
for the Laboratory. Materials have been delivered as recorded media,
LAN servers, the Internet, and in a Computer Classroom used in conjunction
with the Laboratory. Cross-platform issues have been, and still are a major
concern. One overriding observation has been that the availability of electronic
materials for out-of-class use tends to broaden the performance gap between
the top and the bottom of the class. In-class use tends to narrow that
gap. Some of these materials will be made available through an FTP site.
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About the Course:
The University of Missouri-Rolla has been
listed in the top 100 of Yahoo's "Most
Wired Campuses" since the listing began in 1997. All
of our residence halls, fraternity, and sorority houses are wired. There
are approximately 20 WinTel machines, 12 Macintosh Power PC's, and 30 Macintosh
Power PC/Windows machines available on a walk-in basis in the building,
which houses Chemistry, Chemical Engineering, and a small Biological Sciences
Department. Similar numbers of machines, but heavily slanted toward WinTel,
are available in most buildings on campus.
Our student body is heavily oriented to
Engineering (90%) and Science (5%) with average ACT scores of 28, and Chemistry
is required in most of these majors. All students are required to take
a Chemical Safety Course (Chem 4, 1 credit hour) as a pre- or co-requisite
for any Laboratory course on campus. About 20% take this in one concentrated
week prior to classes during Freshman Orientation. The remainder take it
as a daily class during the first 3 weeks of the semester. Only two General
Chemistry sequences are offered, and one of these (Chem 5) is being dropped.
Chem 5 is a one-semester accelerated course (5 credit hours, including
Lab) for students with a strong High School background that will not take
any higher-level Chemistry (about 20% of our students, mostly Electrical
Engineering majors). A small percentage of incoming students are prohibited
from taking Chemistry until they have completed a remedial mathematics
program in Algebra, though a substantial number of these students have
completed High School Calculus. The remainder (many of these are taking
a one-semester Algebra + Trigonometry sequence) take a four hour (Chem
1, 3 hours lecture + 1 hour recitation) course plus a one-hour (Chem 2)
Laboratory in the Fall, then a three-hour (Chem 3) lecture course in the
Spring.
My first-semester Chem 1 class normally
has 100-120 students, primarily from Basic Engineering (they move into
specific engineering areas in their second year) and 6-15 chemistry majors,
plus a few majors from Biological Sciences, Physics, and "undeclared".
They are subdivided into 6 recitation sections. The entire class meets
for three 50-minute sessions per week, then the recitation sections meet
with a Teaching Assistant for one 50-minute session weekly. Recitation
usually involves a weekly quiz which is taken verbatim from assigned problems
or computer tutorials, and remaining time is usually spent working problems
with the TA. The laboratory is separate from the lecture course, though
there is a strong effort to keep the two "in sync".
For the General Chemistry Laboratory, we
use a mixture of modular experiments from Chemical Education Resources,
Inc., and locally - produced experiments. The laboratory course normally
involves one faculty member with overall responsibility, coordinating 6-9
time slots per week in the Fall semester and 1 or 2 time slots per week
in the Spring. Each time slot involves one faculty member, four TA's, and
an assigned grader operating four sections of eighteen students each in
two rooms separated by a stockroom. The students meet in a large lecture
room (equipped with internet access, a dedicated computer, and a permanently-mounted
projector) for approximately one hour to turn in the previous laboratory
report, take a pre-lab quiz (optional for the instructor), and receive
background information (lecture, modifications to procedures, safety considerations,
etc.) on the scheduled activity. The faculty member has primary responsibility
for this presentation, but this is often delegated to the TA's. The students
then move to the laboratories or computer facilities. The lab course has
#1 priority for a computer classroom with 18 machines at 2-person stations,
and high priority for two additional rooms (not so well-designed for classes),
each with 12 machines.
The computer classroom was first used in Fall
'98. It represents the cumulation of about five years of begging, arm-twisting,
and outright pushiness on my part. It was designed with the help of departmental
staff - a research engineer (electronics and computers), an electronics
technician, and a general handyman (glassblower, electrician, cabinet maker,
and upholsterer). They put it together and covered my mistakes. The room
contains 18 Macintosh G3 Power PC's (OS 8.1, 233 MHz, 3 GB HD) with Orange
Pci (Pentium II, 200 MHz, 1 GB HD) boards running Windows 95, with complete
Internet access and password access to practically every server in the
four-campus University of Missouri System. Monitors are embedded in the
2-person desk under a glass plate, so that the room may be used as a conventional
classroom (albeit with a few distractions). There is also an instructor's
machine connected to a ceiling-mounted projector.
I have been developing computer simulations
for both research and teaching since the early 70's (starting on the Wang
Programmable Calculator), following a model that I first proposed in 1967.
Visual components were added in the early 80's, starting with the Apple
IIe Computer. The simulations were developed primarily as lecture aids,
because at that time our average student was not sufficiently familiar
with computers to be able to separate the two learning curves involved
- the use of the computer itself and the material being presented. Those
considerations are no longer applicable as the sophistication of both students
and machines has increased greatly over the years.
While many of today's students are more
proficient in the use of electronic materials than their instructors, there
are still some in the General Chemistry class who are not yet comfortable
using email and the internet. In order to get them "on-line" as quickly
as possible, I have electronic assignments for nominal credit in the first
two weeks of class. The first is a questionnaire
on
the Web regarding the students' expectations for the course, taken directly
from Eric Mazur's book Peer Instruction [Prentice-Hall, Upper Saddle
River, N.J., 1997]. I personally contact any students that do not
respond, and invite them to a help session in the Computer Classroom.
The second assignment
is for the students to email me with their seating preference
in the classroom (if any) and to introduce themselves. The introductions
vary from "Hello, I'm ----." to lengthy discussions of their backgrounds
and plans. These assignments have provided an unexpected bonus, in
that the rapport between me and the class that would normally take a month
or more to develop is almost immediately in place. I feel that I
know the students better, and they seem to feel that they know me better.
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Introduction
There's an old saying, "When the only tool
you have is a hammer, every problem looks like a nail." For my email signature,
I have used the quote, "The practice of Chemical Thermodynamics is simply
a matter of finding the proper wrench to pound on the right screw." Both
of these statements backhandedly make the point that we often choose a
tool because of its availability, not necessarily for its appropriateness
to the job at hand. However, we prefer to hire workmen (carpenters, mechanics,
bookkeepers, technicians, programmers, etc.) who know what tools are required
for the job we want them to do, know how to use them, and either have those
tools or know where to obtain them. Most jobs can be done at varying levels
of efficiency and effectiveness, depending on the availability of different
tools and their costs. Determination of the "best" tool for a particular
job to be done at a particular point in time must be based on the worker's
proficiency with available tools as well as on time and budgetary restraints.
As teachers, we are normally faced with
a specified amount of material that is to be "covered" with a specific
group of students in a fairly rigid framework of time and space. That teacher
must get the job done with that group of students in the best way possible
with the resources available at that time. The traditional tools include
Lecture/ChalkTalk (the all-purpose hammer), Laboratory, Demonstration,
and an assortment of Teaching Aids (posters, slides, overheads, videos,
films, etc.) which might be considered as enhancements for lectures or
even as substitutes for demonstrations. Homework, take-home projects, and
studying for quizzes/exams are employed in an attempt to use out-of-class
time to enhance learning. More recently, cooperative methods utilizing
peer instruction have been added for classroom applications and group projects
for out-of-class participation. The even more recent developments in Distance
Learning are increasing the need for teachers to acquire new tools at an
ever increasing rate.
All of these tools require varying degrees
of preparation and varying dependencies on the resources available to the
teacher. Even the simplest forms of projectors will occasionally fail,
demonstrations will go awry, and supporting materials are delayed or otherwise
not available; often scrapping the planned classroom activity and usually
leaving the instructor to fall back to a less technological method. The
popularity of Lecture/ChalkTalk as a teaching tool probably derives more
than anything else from the fact that it allows the instructor the greatest
control and the least dependency on outside factors. Teachers who are experienced
with cooperative methods may be able to shift to this mode when technology
fails, but for optimal effectiveness, these methods require substantial
preparation on the part of the students. In truth, any effective teaching
method requires preparation by both students and instructor, and the lack
of preparation by one or the other usually becomes apparent rather quickly.
Lecture/ChalkTalk, however, can proceed smoothly with no preparation on
the part of the students (even with a substantial number of them asleep),
and in some cases with little or no preparation on the part of the instructor.
Computerized materials provide another set
of tools that teachers may use to accomplish their task. At the very basic
level, a digital projector and an internet connection allow all of the
resources of the Internet to be brought into the classroom. Alternately,
students may be required to view such materials as preparation for class
or for extended assignments. Contrary to the claims of educational hucksters,
the availability of these materials do not make the teacher's job easier.
Effective use of these materials requires a great deal of preparation on
the part of the teachers - they must locate appropriate software or internet
resources, review them for applicability to the class, and develop a scheme
of preparing their students to receive these materials for optimum effectiveness.
The rapid development of electronic educational materials is both a blessing
and a curse to instructors. The amount of time required to maintain currency
is steadily increasing. Unfortunately, the time and effort spent on this
type of preparation is often not recognized by administrators or even by
other teachers. My assessment of this technology is that it doesn't make
the job easier and it doesn't allow you to do a better job with the same
amount of work - it allows you to do a much better job, but only with the
investment of more time and effort.
In teaching any course, there will be several
stages of development - appraisal of the background of students relative
to course material, getting acquainted, introducing new material, testing,
etc. The available tools will have differing degrees of applicability to
each of these stages, and the applicability of each tool will depend on
the instructor, the students, and the specific material involved. There
will also be some variation in the order of these stages for different
circumstances.
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Appraisal of the Readiness of
Individual Students for the Material, Remediation, and Review
Generally, there will have been campus-wide
testing of the students' basic communications and mathematics skills. A
multiple-choice quiz can quickly provide information on the student's present
strengths and weaknesses in the course material. However, many of the students
took their high school chemistry in either their Sophomore or Junior year,
and their present abilities may give a poor evaluation of how they can
be expected to perform in the course. A personal interview can add greatly
to this evaluation and can have a major impact on establishing student
- teacher rapport, but this can be prohibitively time-consuming for larger
classes. Using the results of this testing to devise a plan to guide the
student's remediation and review is likely to be even more time-consuming,
and will likely require resources that are not available.
A system of self-appraisal and asynchronous
remediation is potentially the most efficient tool for all involved. Computer-based
test/tutorials have been developed for very specific areas related to our
first-semester General Chemistry course - Names
of Elements, Ions, Binary
Compounds, and Ionic Compounds(see
ChemicalNames).
Similar programs have been developed for basic arithmetic skills - Significant
Digits, Prefixes and Multipliers,
and Estimated Calculations, an exercise
designed to make students less blindly dependent on calculators. These
tutorials are available on the Web http://www.umr.edu/~gbert/tutorials.htmland
in Computer Learning Centers (CLC's) on campus. The Course Syllabus states,
"The first 2 Quizzes will cover names and formulas of Elements (Rows 1
- 5 of the Periodic Table) and Ions. You must receive 70% or better on
these quizzes within the first four weeks to remain in the course." In
Fall '99, the four naming programs were accessed over 3000 times over the
Web in the first four weeks of class (and 1000 times over the remainder
of the semester). All of my students passed the quiz on naming Elementsthe
first time (average 85%), 94% passed the quiz on Binary
Compounds (average 90%), but only 75% passed the first quiz
on Ion Names. The percentage passing
rose to 88% after the second Ions quiz, and that number rose to
100% after an evening session that was somewhat "up close and personal".
There is no specific test of mathematical
proficiency, though the students are warned that points will be deducted
for improper use of significant figures and scientific notation. The students
are shown how to access these materials in the first class (a computer,
internet access, and a projector are available in the lecture hall), and
I am available for 2-3 hours one night a week in the Computer Classroom.
No student has ever been dropped for failing to meet the quiz requirements
in the four years I've used this system, though some have dropped voluntarily.
About 4% of my students require a considerable amount of help to meet the
requirements. Very few of these complete the course. The overall "drop
+ failure" rate for this course is about 15%, though that number dropped
to about 5% in Fall '99.
Most of the tutorial programs for General
Chemistry can be used in Assessment, Remediation, and Review
for higher-level courses. A new tutorial Mixing
Solutions (plug-in is required) is being developed for assessing
problem-solving skills, and to help students bridge the chasm between the
way that mathematics is taught and the way that it is applied in Chemistry.
An animated representation of the process, and a requirement for interaction
(trivial as it may be) are expected to aid in the assimilation of problem-solving
skills.
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Interactive Lecture Aids/Simulated
Demonstrations
Many of these materials are available on
the Web for students to use outside of class, but I do not feel that this
is generally an effective use. They were not designed to teach the average
student, but as tools for an above- average instructor. Most of the materials
require a bit of introduction by the instructor, and coordination with
the text or other course material.
The simulation Iodine
Clock Rx (batch) has been used here for over 15 years as a lecture
aid in General Chemistry and in Physical Chemistry II, to introduce the
Method of Initial Rates for determining the order(s) of a reaction. It
was developed on the Apple IIe, and was used in small classes with the
students huddling around a 12" monitor and in large classes with a 60"
3-beam projector. It was also used by other instructors in Physical Chemistry
Lab a few times in lieu of the actual experiment. One semester I found
myself teaching the kinetics unit in both General Chemistry (early in the
semester) and Physical Chemistry (late in the semester). I gave the same
lecture/demonstration using this program to both classes with little other
discussion of Initial Rates, then gave both classes the same problem on
their exams. Both groups scored better than 90% on this problem, which
I had previously rated at about 75% for Physical Chemistry exams. Iodine
Clock Rx (flow) adds another dimension to this presentation,
with the time aspect visually appearing as distance. This has also been
used in higher-level courses to introduce methods for studying fast reactions.
After great frustrations in trying to perform flow experiments in the Physical
Chemistry Lab, I cannot fault anyone for using this simulation in lieu
of the actual experiment.
The visualization in this simulation is
nothing more than a color change, but it demands involvement on the part
of the viewer. This seems to transduce the subject from algebra and calculus
to common sense - if the reaction goes twice as fast, it will take half
as long for the color to appear. If we double the concentration of iodate
ion and it goes twice as fast, it must be first-order because the rate
would have quadrupled if it was second-order, and then it would only have
taken one-fourth of the original time. The algebra and calculus, and perhaps
the chemistry, all make more sense AFTER this frame of reference has been
established. I have on some occasions supplemented this simulation by showing
the actual reaction and the real color change, but the students have always
shown more interest in the simulation than in the reaction. In any case,
the simulation allows the demonstration of many more reaction conditions,
including temperature effects, than could actually be attempted in a classroom
situation. Even if the instructor fouls up in "preparing" the solutions
for the simulation, the mistakes are completely traceable and correctable
with little loss of time and minimal confusion of the students.
My favorite part of using this simulation
comes after we have gone through enough sets of conditions to determine
each of the orders, varying one concentration at a time. Then I prepare
a new set of conditions, varying the concentrations of two components simultaneously,
and ask the class to predict the outcome. I list the predicted times sequentially
on the board, and ask the class to vote on their choices. General Chemistry
classes generate considerably more noise than Physical Chemistry classes,
and the younger students are more scattered in their responses. The older
students are just as interested, but tend to wait for the "top students"
to respond. When the simulated reaction "runs" under the new conditions,
there are scattered "boo's" as predicted times are passed and a big cheer
as the color changes. After two or three episodes of this type, the entire
class is predicting the correct outcome each time.
A simulation pH
Titration (also dating back to the Apple IIe) has been used
as a lecture aid to illustrate many aspects of acid/base behavior. The
comparison of titrations of acids and bases of varying strengths is an
obvious use, but a knowledgeable instructor can also use these curves to
illustrate buffering, concentration effects, polybasic acids, and titrations
of mixtures. This familiarization with the program enables students to
use it on their own in higher-level courses such as Analytical and Physical
Chemistry.
The animation Bomb
Calorimeter Assembly can be used as a lecture aid to add more meaning
to a discussion of Heats of Combustion, especially if the actual
apparatus is not available. This animation was built from the graphics
used in a simulation of the experiment, complete with unknowns, which is
used in Physical Chemistry Lab. Other animations, Buoyancy
and
Dissolution
Processes, can be used as starting points for class discussions.
The simulation Gas
Laws (there are slight differences between the simulation on
the Web and the accompanying program GasLaws)
was developed in an attempt to make calculations on ideal gases more meaningful
to students, by providing visual depictions of the processes and a small
amount of interaction. The program starts with a cylinder being loaded
with a gas at 1.00 atm pressure and an arbitrary temperature (0 to 500°C)
and volume (0.2 to 2.4 L). The web user may then choose a condition to
perform a process (constant temperature, pressure, or volume), then operate
controls to change one property and watch the other unrestrained property
respond. A question or problem may be requested, yielding a question based
on the current condition of the apparatus asking about the response to
a specific change in one of the properties. The controls are frozen until
an answer is provided, then the user is allowed to operate the controls
to impose the new condition and observe the response.
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Tutorials for Self-Study
Ten of the tutorial exercises were specifically
assigned to Chem 1 in Fall '99, such that students were responsible for
this material on recitation quizzes. These ten exercises were accessed
via the Internet a total of 2961 times during the semester with about 20%
of the accesses coming near the end of the semester, apparently as a review
for the final exam. These exercises are also available on the 42 Macintosh
computers in CLC's in the building, and these were heavily used in the
week before the final exam. My experience has been that even the
top students do not use these tutorials unless they see a direct or indirect
payoff,
such as a high correlation between the quizzes and the tutorials.
Poorer students do not use them unless there is a direct payoff, as in
credit for an assignment. This has led to what is known on campus
as Bertrand's Adage , "No credit - forget it!", and to a broadening
of the gap between the top and bottom students in the class.
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Simulations in the General Chemistry
Laboratory
Simulations have been used extensively here
for pre-lab lectures for about five years. We use a complete simulation
of the experiment Colorimetry and Spectrophotometry that our students
perform in the laboratory. The Colorimetry
(see
clrSpec) part of
the experiment is available on the Web. Students prepare a set of calibrated
standards by mixing dyes and water dropwise, and estimate the concentrations
in two unknowns, a diluted dye and a mixture of two dyes. In the Spectrophotometry
part of the experiment, a Spectronic 20 Spectrophotometer is used to analyze
the same unknowns. The program has built-in instructions for operating
both the real and simulated instruments. For demonstration purposes,
the simulation has a couple of features that are not available on the actual
instrument, autozero and autoscan. The latter produces
the spectrum of the sample from 400-700 nm, and allows comparisons of several
spectra. The simulation allows the instructor to run through the
entire experiment projected onto a large screen in about 10-15 minutes.
The experiment then runs very smoothly in the laboratory, even though it
is complicated by half of the students starting on Colorimetry and
half starting on Spectrophotometry, to relieve stress on the instruments.
We have used the modular experiment, "Statistical
Analysis of Experimental Density Data" [PROP 353, Chemical Education Resources,
Inc.], for several years. Several samples of 5 - 8 glass beads (boiling
stones) taken randomly from a large supply are either weighed or their
volume is measured by displacing water in a buret. Means and standard deviations
are determined, and the density and its uncertainty are calculated from
the mean mass and mean volume. In Fall 96, we began using the simulation
Glass
Beads (beads) in conjunction with
this experiment, using the two small computer rooms that were then available.
The simulation allows the user to choose the number of beads to be delivered
either to a balance for weighing, or to a volumetric device (something
of a cross between a buret and a graduated cylinder) containing a liquid.
The simulation may be operated so that the beads for the two measurements
are completely randomized, or they may be "coupled" so that the same samples
are used in the mass and volume determinations. The instruction sheets
that are placed at each computer station are included in the GlassBeads
folder, along with copies of the data sheets and the Excel spreadsheet.
The simulation is used by the instructor
as a lecture aid in discussing the experiment. Half of the students then
begin the experiment in the laboratory and half on computers. Data is taken
in both phases of the experiment, but the simulated data (which contains
randomized variations) is transferred to a spreadsheet template for statistical
analysis. I consider this an optimal use of a simulation. In the actual
experiment, the students learn (admittedly just a little) experimental
technique of using a top-loading balance and reading a buret, and they
are exposed to some sources of error that are not easily simulated (miscounting
beads, contaminating the beads with extraneous materials, leaking burets,
etc.). There is a rapid dropoff in the benefits realized per unit time
in the actual experiment. The computer simulation, however, generates large
quantities of realistically scattered data in a very short time. The simulation
is also available for students to re-do on their own. A surprising number
of students do this in the evening after their lab, and the most common
explanation is "my partner hogged the computer".
While not required in the lab, the simulation
can be used to probe more deeply into statistics, such as how the variance
of the set and the variance of the mean are affected by varying the number
of repetitions and/or the number of beads in the set. The students are
encouraged to compare the observed deviations from the mean to the statistical
predictions. A discussion of Uncertainties
is available on the Web, provided for Physical Chemistry
students, and as much for the General Chemistry Teaching Assistants (who
are very inexperienced in processing experimental data) as for the students.
We have recently added the simulation Nuclear
Decay to the General Chemistry Laboratory. For many years, we
have used a Radioactivity "experiment" in this laboratory. The students
receive a lecture/discussion on nuclear notation, particles, and reactions,
and on first-order decay. They then go in groups of 20 to our campus reactor
to see a sample of aluminum irradiated and the gamma radiation counted
for several half-lives. In the past, their lab report was basically two
graphs, counting rate vs time and the corresponding logarithmic plot. Beginning
in Fall '98, they receive the same lecture, then go either to the reactor
or to a computer classroom. In the computer classroom, they perform the
simulation, logging in with a code that gives each pair of students a unique
"reaction" to study. They obtain data at two or more levels of radiation.
They estimate the half-life from direct observation of the time required
for the counting rate to be halved three or more times, then they enter
the data into a spreadsheet, create graphs, and obtain the rate constant
(and the half-life) by regression analysis. This group then goes to the
reactor and the other group works with the simulation.
Computers were introduced into the General
Chemistry Laboratories (one computer shared by a group of four students)
in Fall '98, using the Vernier Lab Interface on old computers retired from
our Computer Learning Centers. These are presently used in experiments
on Colligative Properties and Gas Chromatography. A new experiment
on pH Titrations will be added in Fall '00, utilizing the simulation
pH
Titrations in the Computer Classroom, and in the pre-lab lecture.
The General Chemistry Laboratories were
renovated in Summer '99. Early in the process, we became aware that they
would not be ready for use until the third week of the Fall semester. We
decided to use a simulation, Buoyancy Programs [J. Chem. Educ: Software,
Vol. 7C (1), July 1995], to be followed by the Glass Beads simulation discussed
previously. The buoyancy simulation was modified to include individualized
unknowns, and a formal "experiment" was prepared. An animated mini-lesson
was also prepared for a pre-lab introduction via the internet.
In this "experiment" the specific gravity of two known solids and an unknown
solid are determined by two simulated techniques, then the densities of
two known liquids and an unknown liquid are determined.
Another simulation Gaseswas
designed as a pre-lab for an experiment that was originally developed for
the General Chemistry Lab. We have not been able to overcome the logistical
problems in using this
experiment in the large labs, but I have used it on a smaller scale
in the Physical Chemistry Laboratory. The students are assigned an unknown
gas, and its molecular weight must be reported correctly for a student
to be allowed to actually perform the experiment. The Bomb Calorimetry
Simulation mentioned earlier is also used in this way as a pre-lab
experiment with an unknown for the Physical Chemistry Laboratory. Another
simulation of Freezing Points of Binary Mixtures is used in Physical
Chemistry in lieu of an experiment. Using the simulation, students determine
the freezing point depression constants of two solvents, and determine
the molecular weight of their "unknown" in both solvents. The simulation
allows acquisition of data over a range of compositions, such that extrapolation
techniques are required to obtain the "best" values for the unknown. The
students perform another experiment in which cooling curves are actually
observed, Solid - Liquid Equilibrium in a Binary System, so that
the experimental aspects of freezing point depression are not overlooked.
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The Future
I have encountered a number of impediments
in using Simulations as part of the teaching process, but these are rapidly
disappearing. In the early days, students were overpowered by the compounded
complexities of interacting with the computer, the crude visual presentation,
and the general problems of assimilating the concepts that were presented.
Today's computer-wise students arrive with sufficient skills to minimize
the amount of time that must be spent on the mechanics of the operation.
This has been made possible by the advances in speed and sophistication
of the machines and their operating systems, as well as the general experience
of the students in using computers throughout their education. I estimated
that only about 2% of my students this year were uncomfortable with the
use of computers as part of class or assignments, by the time they had
finished the first semester.
I believe that the major advancement has
been in Accessibility - access to the machines is obviously important,
but access to materials is even more important. The Internet has opened
many of these doors, not only to software that can run directly through
a browser, but also in access to FTP sites and in simplifying the procedure
of downloading programs and other materials. In the past two years I have
shifted the delivery of more than 90% of my materials from campus servers
to the Internet. Recent developments in simplifying and lowering the costs
of preparing CD-ROM materials are increasing accessibility. Cross-platform
issues will probably continue to impede the development and dissemination
of interactive materials to some extent. The materials made available
through FTP were developed with Oracle Media Objects (OMO), which
is no longer supported by Oracle. The Web materials were developed
with SuperCard and are delivered via the SuperCardWeb Plug-in,
but the internet mode of this authoring environment is not nearly as robust
as the parent program. I have started working with Macromedia's
Director and Shockwave/Flash Plug-in for Web delivery, but I
find the movie metaphor of this system very restrictive for the type of
interactive software that I develop.
In the very near future, students in ordinary
classrooms will have greater access to electronic materials than my students
presently have in our Computer Classroom. Every student will have some
type of monitor at their desk with access to the Internet and various Intranets
or Servers, most likely through wireless connections. Guided access to
Simulations and Simulated Experiments will bring the flavor of the laboratory
into the classroom (without the smells).
The major disappointment that I have encountered
in developing and using electronic materials in my teaching is that only
one of my fellow faculty members has used these materials in his classes.
There has been general recognition by other faculty of the effectiveness
of these materials, and there has been a slow but steady increase in usage
by Teaching Assistants in Recitations and Laboratories. There is perhaps
an element of "trying to teach old dogs new tricks" here, since of the
seven faculty who have been involved with General Chemistry Lecture Courses
over the past two years only two are under the age of sixty, and those
two are heavily involved in Research and/or Administration. There can be
no doubt, however, that there is a large activation barrier even for young
faculty to develop the expertise for using these materials in a classroom
situation, and this barrier grows with every year in the classroom. The
REAL evolution of the use of these materials will be hastened by the recognition
of these barriers by administrators, and provision of time, materials,
and credit for faculty to develop the expertise to overcome them.
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Notes on Downloading:
1. Macintosh - Before starting the process, check your browser's setting
for the downloading destination. (Windows will usually allow you
to select this in the downloading process) It is best to create a
specific folder and direct the download to it, so that the materials will
be kept together.
2. Depending on the extraction software on your machine, the file may
still have the .hqx suffix, only the .sea or .zip
suffix, or it may have been extracted to the operating components.
3. Expand or Extract the files if necessary. It is important
that the un-zipping file be set to "maintain folders (subdirectories)"
or "recurse folders".
4. Check the expanded files against the listing below - there is sometimes
a problem with the OmoWin folder in Windows, in that the three subfolders
do not appear, and the individual files are scattered. If this happens,
folders with these specific names must be created and the proper files
must be placed in them.
5. To run a Program, double-click on its icon. Under Windows,
you will probably be asked to locate the application through a dialog window
named Open With. Clock on Other at the bottom of the
window. Locate Omoplay.exe in the OmoWin folder, and
the program should run.
Compressed Files: (to be downloaded)
Macintosh:
CCSim.sea.hqx
OmoMac.sea.hqx
Windows:
CCSim.zip
OmoWin.zip
Expanded Files: (suffixes may not appear)
CCSim:
Folder - Colorimetry
clrSpc.STA (Program)
colorimetry.msw
colorimetry.wpd
Folder - GlassBeads
beads.STA (Program)
GBds_DS.MSW
GBds_dir.MSW
spreadsheet.XLS
ChemicalNames.STA (Program)
GasLaws.STA (Program)
gases.STA (Program)
Player (Macintosh) or OmoWin (Windows):
Folder - Library
System (Program)
Folder - License or Distribution License and Agreement
These items are not used
Folder - Objects
Windows - 7 files with suffix
.mox
Macintosh - 15 files like Bitmap(Player)
Omoplay.exe (Windows)
or
OMOPlayer (Macintosh)
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Setting up the Windows SuperCard Plugin with Netscape
(best with Netscape 4.5)
This applies whether you have Netscape only , or both Explorer and
Netscape.
Download the Plugin from the SuperCard site, and decompress it.
Find the Netscape Folder on your Hard Drive (C: drive)
Determine whether you have Communicator + Navigator, or just Navigator
Find the Application "SCPlugin_setup" (it's where you directed
the download)
Double-click on the icon for "SCPlugin_setup"
A message box will appear "Pre-setup will prepare ..." Click on
"OK"
You will see the time bar filling in.
Click on "next" until you see the window: DIRECTORY
Click on "Browse"
Locate the Plugin folder for Netscape Communicator (or for Navigator
IF you don't have Communicator):
It is usually on the path:
Win95(C:)/Program Files/Netscape/Communicator/Program/Plugins
Click on "next". (as many times as is necessary)
Let's hope that it tells you that the installation was successful.
Quit that application.
Start Netscape. Go to http://www.umr.edu/~gbert/tutorials.html
Click on one of the tutorials with the Windows flag.
Let's hope that it runs
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