6th edition 9.11


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Julia Lung 1I
Posts: 30
Joined: Fri Jun 23, 2017 11:39 am

6th edition 9.11

Postby Julia Lung 1I » Thu Feb 14, 2019 11:59 am

Calculate the change in entropy when the pressure of 1.50 mol Ne(g) is decreased isothermally from 15.0 atm to 0.500 atm. Assume ideal behavior.
I got the right answer for this problem using ΔS=nRln(P1/P2) = ΔS=(1mol)(8.314 J/k*mol)ln(15.0atm/0.500atm) = 42.2J/K but I'm confused how the units cancel because the R constant that I used is J/K*mol that is not L*atm/K*mol even though the pressure is using atmospheres.

Emily Ng_4C
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

Re: 6th edition 9.11

Postby Emily Ng_4C » Thu Feb 14, 2019 12:32 pm

When you divide the pressures, the atm's cancel each other out. Your ending units should be J/ K.

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