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On 06/26/14 00:32, wrote:<br>
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cite="mid:C40B2F181831EF44A88CD73525827803130774D595@MERCERMAIL.MercerU.local"
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<pre wrap="">Hello Dr. Pounds,
I'm stuck on one of the additional problems (Chapter 11, problem 4). In the first part of the solution
q=[(506 g)/(18.0 g/mol)] (6.01 kj/mol) is used. What is this equation and why is it used?
Thank you,
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<br>
This is an energy balance thing (look back at section 5.4 of your
text), if there is not enough energy released to cool the water,
then some of the ice will still be in solid form.<br>
<br>
q is the "heat" required to melt the ice. You have to determine
this by computing <img style="vertical-align: middle"
src="cid:part1.04060902.03050004@mercer.edu" alt="$\Delta H$"> for
the reaction<br>
<br>
H2O (s) -> H2O (l)<br>
<br>
If you use the tables in the back of the book, you will get
something close to the value I have on the solutions. Now, this is
per mole of ice, so I have to figure out how many moles of ice I
have, that is where the ratio (506 g)/(18.0 g/mol) comes into play.<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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