| Product Name: |
Chemistry PreLabs II (OzChem) |
| Level: |
First Year Tertiary |
| Platform: |
Macintosh® / PC - Windows® |
| Supplied Information: |
Chemistry PreLabs - Chemistry Laboratory Preparation
simulation program, [CD-ROM]. Practise your experimental techniques and skills in safety, before entering the real chemistry lab. Carry out simulated experiments covering a range of basic chemistry topics. Students receive different sets of data which adds to the realism. Each prelab may be completed as a pre-cursor to the real thing as part of a virtual laboratory course. Each prelab contains videos of the techniques required to complete the experiment safely and gives students access to the information they need, through a stack of reference books. The books include a glossary and a compendium of materials safety data. By using ChemTrak with the prelabs, a teacher can monitor a student's progress. There are 12 prelabs on the CD, which cover basic experiments on the following topics: 1. volumetric analysis; 2. oxidation-reduction; 3. oxidation states of vanadium; 4. molar mass of an active metal; 5. chromatography; 6. preparation of aspirin; 7. determination of a rate constant; 8. determination of vitamin C; 9. analysis of 'radox' bath salts; 10. acid-base titrations; 11. solubility equilibria; and 12. corrosion of metals. |
| Possible Use: |
This product is suitable for First Year Tertiary courses for use by students in laboratory classes. |
| Review: |
This program invited me (with an uncontrollably loud voice) to put on the
required safety lab coat and glasses, pick one of the 12 first year level
experiments on offer, and enter the virtual lab wearing my gum boots (well
that's what it sounded like!) through a squeaky door. The virtual scene was
graphical rather than a photographic image of a real lab.
I like baths so I chose to analyse Radox Bath Salts. A lab notebook gave me
instructions on what to do next, and I had access to:
Ö a calculations book with spaces for me to insert calculations, with a
calculator to help me;
Ö a techniques book with text and Quicktime movies describing a range of
experimental procedures;
Ö an equipment book to describe the glassware I would be using;
Ö a chemicals book with brief safety information on each chemical I would use; and
Ö a glossary book with brief meanings for important terms.
This titration experiment required me to use a pipette to transfer 25.00mL
of Radox solution. The only way I could do this was to click and drag the
pipette to the volumetric flask and remove the solution directly from the
flask. I didn't think this was good technique so I checked with the
demonstration movie in the techniques book and was shown, more correctly,
solution removed from a beaker using a pipette. One of the problems with
using graphical simulation in a virtual lab is that there are inevitable
simplifications. Whether they can reinforce or lead to poor technique is
debatable.
I was able to click and drag my way through three titrations using a clever
simulation of using a burette. However, in each case I was not encouraged,
or able to:
Ö do a rough titration to find the approximate end points, without having
to count it in my titre averaging;
Ö add solution with split drops; and
Ö read the burette clearly to two decimal places.
However, perhaps this fine tuning is best taught in the real wet lab, and
the function of the simulation is to give a simplified overview. The videos
on this and other techniques could be criticised by an analytical chemist
for small omissions, and by a video producer for not showing sufficient
close-up views, but once again, the fine technique details should come
later in real time, with directions from a real demonstrator.
The calculation protocol requires a stepwise progression of
mini-calculations set out for the student, without any need for thinking.
Not all chemists work this way - many accumulate the steps into one long
calculation at a suitable point. This habit is recommended to avoid
compounding rounding-off errors. I would also have preferred to see units
associated with every quantity, and cancelled out, to encourage students to
think about any unit conversions required, and as an internal audit of
correct formula rearrangements. However, perhaps these calculations are
also designed as an overview before students have to do the real thing in
the lab on their own.
Despite some strange sound effects, a calculator that must be turned off
before you can type in a result, and some pedantic criticisms of technique,
this program provides a useful 'dry run' to a variety of common
experiments. As such it is a good solution to the problem of encouraging
students to preview an experiment without stress, before they enter the lab
with an over-zealous demonstrator looking over their shoulders.
[Author's response: ïstudents are not expected to include titration results if they are not within the range required. Indeed the results will not be accepted if they use all values in such an instance.
ïburette readings are required to 2 decimal places- the last figure is always
estimated even in the wet lab.
ïstepwise calculations are provided to assist those with low short term memory capacity in these early stages of tertiary chemistry.
ï an important feature is that students may access the material at their own
pace and when and as often as they wish in their preparation on either a PC or a MAC.] |
|
Dr Roy Tasker, School of Science,
University of Western Sydney, Nepean 12/3/98 |
| |
| Supplier: |
Centre for Educational Development and Interactive Resources, University of Wollongong. Northfields Avenue, Wollongong, NSW 2522 |
|
imp@uow.edu.au |
|
phone: 612 - 42214 895 |
|
fax: 612 - 42258 312 |
| Date Record Last Modified: |
25/6/98 |
