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<div class="moz-text-html" lang="x-unicode"> <big><font
size="2"><big><big><font size="2"><big>I'm getting
questions about exp 16 and the pre-lab. We<br>
weren't able to get to freezing point depression
in section<br>
13.5. The manual has a discussion with everything
you<br>
need for the lab and pre-lab.<br>
<br>
If you took 1250 previously exp 16 has changed
slightly. The<br>
volume of the solvent (cyclohexane) has changed
and the masses<br>
of solute added (and total mass) in each trial
have changed.<br>
The Data Analysis section of the manual still uses
20.00 mL of<br>
cyclohexane in the example on page 102. The new
volume is<br>
10.00 mL.<br>
<br>
Look a the "Laboratory" link on my class web page
for additional<br>
help for exp 16. Do this before lab, while
writing up your procedure<br>
and before doing the pre-lab.<br>
<br>
You will need to collect some temperature data
which will not<br>
wind up on the report sheet. Make allowances for
this in your<br>
notebook. You need to do at least 3 f.p.
"determinations" for each<br>
f.p. you see on the report sheet. You may have to
do more than<br>
3 f.p. determinations. You do them until you get
3 f.p. w/in 0.1 degC<br>
of each other (e.g. 6.1, 6.3, 6.2). Then you take
the average of these<br>
three. Report your answer to ONE decimal place
(you can't gain a<br>
s.f. when averaging only three numbers).<br>
</big></font></big><br>
There is a data-entry pre-lab. You won't understand
what you<br>
are supposed to do with the numbers given if you don't
carefully<br>
read the manual and write the procedure first.<br>
<br>
Reminder, </big></font></big>f<big><font size="2"><big>or
the on-line data entry you really need to do it in one<br>
sitting. When you don't we can't guarantee what will
happen.<br>
Don't walk away since it could time out and if it does
it will start<br>
over from the beginning. Also, if you do it by clicking
the link<br>
in Carmen your time limits will be based on those of
Carmen.<br>
You are better off clicking on the links in the
syllabus. Even so,<br>
don't plan on getting an unlimited amount of time to
work on these<br>
and not get timed out by the server.<br>
<br>
Read the directions. I'm finding a number of people
didn't for<br>
exp 14 pre and post-lab. There's an "Instructions"
button<br>
in the top left-hand corner on the page. Click on the
"policies<br>
and procedures" link at the bottom of the page before
starting.<br>
I sent this as well in a previous link.<br>
<br>
Also, if you have problems please send me ALL the
information I've asked<br>
for in a couple of previous e-mails. Also, take a
picture or do a screen capture<br>
and send these as well.<br>
<br>
Dr. Zellmer</big></font></big> </div>
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