Quiz 1 Preparation


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Vanessa Romero-Campos 2B
Posts: 39
Joined: Fri Sep 25, 2015 3:00 am

Quiz 1 Preparation

Postby Vanessa Romero-Campos 2B » Tue Jan 31, 2017 4:10 pm

#3 If 2 mols of an ideal gas at 300 degrees K and 3 atm expands isothermally and reversibly from 6 to 18 L and has a final pressure of 1.2 atm what is its w, q, and delta U?

To find the work I used -n*R*T*ln(v2/v1) and plugged in the values as follows

=-2*8.206 *300*ln(18/6)
=5409.127 L*atm
and to convert to joules I multiplied by 101.325 since 1 L*atm=101.325 J, then I converted into kJ by dividing by a 1000 but ended up getting -548.0 instead of the answer 5.4 kJ.

Can anyone explain to me where I'm going wrong either in the conversion or numbers I used?

Angela To 2B
Posts: 20
Joined: Wed Sep 21, 2016 2:55 pm

Re: Quiz 1 Preparation

Postby Angela To 2B » Tue Jan 31, 2017 4:14 pm

It's your R value! It should be 8.206 * 10^-2 L*atm/mol*K

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