Homework Question: 8.49

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Maddy_Larson_2J
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Joined: Wed Sep 21, 2016 2:59 pm

Homework Question: 8.49

Postby Maddy_Larson_2J » Sat Jan 21, 2017 8:58 pm

For question 49 in the homework we have to use the equation deltaU=deltaH-PdeltaV to solve for the internal energy. I found H and PV (using the ideal gas equation) and I subtracted them but since PdeltaV was a negative value I ended up getting -318-(-2.47)=-315.53; however, the book got -318-2.47=-320. Did I make a math error, or misplace a negative sign? Or did the book make a mistake? Which answer would be correct? Thank you!

Selena_Wong_1I
Posts: 13
Joined: Wed Sep 21, 2016 2:56 pm

Re: Homework Question: 8.49

Postby Selena_Wong_1I » Sat Jan 21, 2017 9:12 pm

The equation is delta U= q + w.
q= -318
w= -2.48
So the book is correct; you add q+w together to get -320 ( you subtracted w from q).


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