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On the report sheet on page 125 for exp 17 you list the 4 rate
constants<br>
for the 4 solutions. Then you are supposed to take an average and<br>
calculate the average deviation. Technically you should also check
to<br>
see if you should include all four rate constants in the average
(i.e.<br>
is one of them really different than the other three). To do this
you<br>
should do an error analysis.<br>
<br>
All of this is explained in the following link (which I sent
previously<br>
in an e-mail about exp 16),<br>
<br>
<a
href="http://chemistry.osu.edu/%7Erzellmer/chem1220/lab/App_D_122_lab_manual.pdf"><b>Treatment
of Numerical Data (Error Analysis, sig. fig., graphing)</b></a><br>
<br>
This link can be found at my "Laboratory" link. If it's
questionable which<br>
graph (1st or 2nd order) has more parallel lines you can calculate
the<br>
average deviation for the rate constants for each graph. That can
help<br>
decide which set of lines might be more parallel.<br>
<br>
Of course all of this depends on you calculated things correctly,
especially<br>
your initial conc. of Cr^3+ in each solution (remember, the 4 solns
should<br>
have different [Cr^3+]_o). I've seen data or spoken to 4 people
just today<br>
who've made such mistakes.<br>
<br>
Dr. Zellmer
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