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I've received some inquiries about exp 5 and the pre-lab.<br>
<br>
Since we finished some of the material that applies to exp 5 I
wanted<br>
to make sure you could answer all the questions from just the lab
manual.<br>
The majority of what you need to complete the pre-lab is contained
in the<br>
lab manual for exp 5. You will need an understanding of formula
weights, <br>
the "mole" and molar mass. These are covered in sections 3.3 and
3.4.<br>
For further reading on ionic equations, acids and bases, and
neutralization<br>
reactions see sections 4.2 and 4.3. Solution stoichiometry and
titrations<br>
are covered in section 4.6. You should consider waiting to attempt<br>
the pre-lab until you've finished learning this material and doing
the<br>
homework for these sections. You pretty much need to w/in the next<br>
day or so any since we have a review and test coming up.<br>
<br>
Before attempting the pre-lab you should read the Discussion section<br>
and review the calculations. Write the procedure so you have some<br>
idea where the numbers are coming from. Watching the video at home<br>
before writing the procedure will help (you can find the videos on
my<br>
web page at the "Laboratory" link). It will give you better idea of
what's<br>
going on so the procedure makes sense. The procedure MUST be<br>
written in your own words in an outline form similar to my example<br>
on the last page of the syllabus (and found at a <a
href="http://chemistry.osu.edu/%7Erzellmer/chem1250/lab/notebook_proc_1250.pdf">link
</a>on my class web<br>
page). Pay attention to the equations and the examples in the
manual<br>
since the calculations you'll be doing are very similar. <br>
<br>
In Part A of the exp you'll be using something with an acronym of
KHP.<br>
People often mistakenly think KHP is potassium hydrogen phosphorus.
<br>
It is <b>NOT</b>. KHP is an acronym for potassium hydrogen
phthalate,<br>
KHC8H4O4. It is a salt consisting of K<sup>+</sup> and HC8H4O4<sup>-</sup>.
The latter<br>
is a weak monoprotic acid (hydrogen phthalate).<br>
<br>
The link for the pre-lab is in the syllabus, on Carmen and my web
page so <br>
if the following doesn't seem to work from your e-mail you can find
it <br>
somewhere. <br>
<br>
<a class="moz-txt-link-freetext"
href="https://uglabs.cbc.osu.edu/1250/pre-postlabs.php">https://uglabs.cbc.osu.edu/1250/pre-postlabs.php</a>
<br>
<br>
This will take you the main Chem 1250 pre and post-lab page.<br>
READ this page and the Terms and Conditions of Use if you didn't<br>
do it already.<br>
<br>
The pre-lab essentially consists of two parts. The first part
starts with<br>
a video, which you need to watch all the way through (including the<br>
credits) or you will have have points deducted. Then there is a
series<br>
of questions dealing with the discussion and procedure in the manual<br>
and the video. <br>
<br>
Below this part is the data-entry part of the pre-lab. You'll be
given<br>
numbers similar to what you'll obtain in the actual experiment. You
will<br>
then do the appropriate calculations and enter the numbers (make
sure<br>
you have the correct sig. fig.). That's pretty much it. <br>
<br>
Once you click on the pre-lab or data-entry links you'll get a new
screen.<br>
There is an INSTRUCTIONS button in a red box toward the upper-left
of<br>
the page. Click on it before you start. Pay attention to what it's
telling you<br>
to do in terms of units, how to enter the numbers, etc. The program
will<br>
send you an e-mail if the pre-lab was submitted correctly. Also,
the screen<br>
should refresh with your entries and results and score. If it
doesn't it didn't<br>
submit properly.<br>
<br>
Dr. Zellmer
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