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<div class="moz-cite-prefix">On 11/18/2015 03:37 PM, wrote:<br>
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cite="mid:c330d7dba28b4be6aaaf5e2aa78daaa3@spiderman.MercerU.local"
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style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">Dr.
Pounds
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<div>What value do we use for the epsilon variable in Beers' law
formula (A = c × l × e)? Is it 262.9?</div>
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<div>Thanks </div>
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Whoa! No.<br>
<br>
You have calculated the concentration (c) and you measured the
absorbance (A). Beer's law simply shows us that there is a linear
relationship between concentration and absorbance. Therefore you
plot the absorbance on the Y-axis and the concetration on the X-axis
and fit a line to that. The path length and epsilon are tied up in
the "slope", but they are irrelevant for the calculations you are
doing.<br>
<br>
I have placed a sample plot on the class website.<br>
<br>
<br>
You use the molar mass of the nickel sulfate hexahydrate (what I
think is your 262.9 number above) when calculating the
concentrations. <br>
<br>
Keep the questions coming if you have them.<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Andrew J. Pounds, Ph.D. (<a class="moz-txt-link-abbreviated" href="mailto:pounds_aj@mercer.edu">pounds_aj@mercer.edu</a>)
Professor of Chemistry and Computer Science
Mercer University, Macon, GA 31207 (478) 301-5627
<a class="moz-txt-link-freetext" href="http://faculty.mercer.edu/pounds_aj">http://faculty.mercer.edu/pounds_aj</a>
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