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MERLOT II


    

Peer Review


Virtual Chemistry Laboratory

 

Ratings

Overall Rating:

5 stars
Content Quality: 5 stars
Effectiveness: 5 stars
Ease of Use: 4.7 stars
Reviewed: Apr 26, 2006 by Chemistry Editorial Board
Overview: The IrYdium Project site is a site hosted by Carnegie Mellon University and
provides a collection of Java based applets that simulate chemical interactions.

The premier applet for the site is the Virtual Lab, which is an extensive applet
that simulates activities that take place in a chemistry laboratory. There is a
stockroom where the user can checkout solutions, glassware, pipettes, burettes
and Bunsen burners. There is a workbench where solutions can be mixed, diluted
and titrated. There are also panels that provide information about a selected
solution, including the identities and concentrations of the solute components,
the pH and the temperature. The Virtual Lab provides an array of example
homework problems, each with a detailed description of a problem that can be
investigated using the Virtual Lab along with a stockroom stocked with the
appropriate reagents and supplies for attacking the problem. In addition to the
applets, the site provides informational resources on the philosophical approach
taken in developing the applets and on incorporating them into a curriculum.
The students targeted are those taking introductory chemistry courses at the
college level. The IrYdium Project represents the fruits of a project that has
received over $1 million in funding from a collection of sources including the
National Science Foundation, the Howard Hughes Medical Institute and Carnegie
Mellon University. The site also provides a useful list of links to similar
efforts being carried out by others
Learning Goals: The stated goal of the site is to provide faculty with Web-based tools that they
can use to help students become more engaged in their chemistry studies and to
better connect with chemical concepts. While the main aim is to learn the
fundamental concepts of general chemistry (Thermodynamics, acid-base chemistry,
stoechiometry, equilibria, solubility, among many) through experimentation which
could be of a directed inquiry nature.

Target Student Population: This site is most appropriate for students taking a course in high school
chemistry or at the university level, a coure in general chemistry or
quantitative analysis.
Prerequisite Knowledge or Skills: An introduction to acids and bases and pH titrations as well as the function of
common glassware and what item is appropriate for a given process - i.e. when
does one use a pipet, or a volumentric flask, etc.


Type of Material: The primary focus of the site is the Virtual Chemistry Lab, which is a highly
interactive Java applet that simulates a chemistry laboratory. It provides
glassware and a large stock of common chemical reacgents that can be used to
carry out a wide rage of titration type experiments
Recommended Uses: Virtual Lab can be used by instructors to demonstrate the procedures and results
of titration experiments. It can be used by students in pre- and post-lab
activities of predict or analyze the results of experiments which they carry out
in the lab.
Technical Requirements: Because the applets are Java based there is a wide range of results obtained
when viewing them with different combinations of operating systems and browsers.
This reviewer found that using Internet Explorer under Windows 2002 worked
consistently well. On the other hand, the results were quite varied when using a
variety of different browsers (Netscape 4.7, 6.2 and 7.0, Internet Explorer
5.2, OmniWeb 4.1 and Safari 1.0 beta) under Mac OS 9 and Mac OS X. For Mac OS X
it is important to use a release of the Java Runtime Engine that is Java 2
Standard Edition v 1.3.1 or later. For Mac OS X, the most consistent results are
currently obtained by using the Netscape 7.0 or Safari browsers, or
alternatively, the Applet Launcher application that comes with the operating
system, instead of a browser.

Evaluation and Observation

Content Quality

Rating: 5 stars
Strengths: The quality of applets is good. The Stoichiometry and Equilibrium applets
provide a simple yet effective way to investigate the concentrations of the
reactants and products in a small set of chemical reactions. The Virtual Lab
also works very well in allowing the user to simulate laboratory activities. For
example, a user can perform an acid/base titration by first checking out the
desired acids and bases from the stockroom along with an indicator and pipettes
and burettes for dispensing and mixing solutions. The user must manually perform
each step in the procedure. When pouring or dispensing liquids from the burette
there is very creative control for pouring liquids that nicely simulates how it
is actually done in the lab. When using the burette the user can read the
burette in the same way that they would do it in the lab. for example, I really
appreciated the gradual change in indicator color as I performed a titration. I
added 0.01 mL at a time and the progressive change in color was well done as
was the accompanying pH meter. At any point in an experiment, a solution can be
selected to query the pH and concentrations of the solute components. The
Virtual Lab works very well as an adjunct to homework problems and pre-lab
assignments.
Concerns: It would be nice if more reactions were available for the Stoichiometry and
Equlibrium applets.



Potential Effectiveness as a Teaching Tool

Rating: 5 stars
Strengths: The applets found at the IrYdium Program site, particularly the Virtual Lab
site, can be very easily incorporated into a General Chemistry or Quantitative
Analysis Curriculum. As the authors make clear, the intent of the applets is not
to replace traditional methods of predicting the outcome of chemical reactions,
but rather to confirm the outcome of those calculations by simulating in a
fairly realistic and engaging way, how those reactions are carried out in a
chemistry laboratory.

Concerns: Instructors should initially introduce students to this software in either a
classroom setting or else using a TA to demonstrate the site and its potential
in a computer lab.


Ease of Use for Both Students and Faculty

Rating: 4.7 stars
Strengths: The interface for the Virtual Lab applet is very intuitive and well documented.
The other applets are less well documented and therefore less intuitive to use.
Most of the applets are simulations that provide consistent and appropriate
feedback. For the combinations of operating systems and browsers for which the
applets work, they do work well.
Concerns: See the caution above.

If run as an applet, there is a significant startup time as the system loads.
If run in stand alone mode, the startup is virtually instantaneous.

The Virtual Lab Step-by-Step Demonstration print material could be made a little
clearer. Thus in the "Local Homework" box, why not highlight "Step by Step
Demonstration" or use this term rather than "select the sample problem"? Why do
I have to choose a volume when I use a disposable pipet? Why do I have to
choose a volume when I empty either it or any other pipet? The print material
uses "pipette" whereas the software uses "pipet" - there needs to be conformity.
Titrate with volumes of ~0,5 mL will not enable one to see "a slight color
change" Get down to 0.05 mL and then to 0.01 mL and one will see a great
demonstration of the color/pH change.

Other Issues and Comments: The Virtual Lab is an excellent example of what I believe the MERLOT project is
trying to promote in terms of web-based learning objects that can be used to
augment a wide range of learning activities.