## Help with Self test 9.4A

Volume: $\Delta S = nR\ln \frac{V_{2}}{V_{1}}$
Temperature: $\Delta S = nC\ln \frac{T_{2}}{T_{1}}$

Miya Eberlein 1J
Posts: 29
Joined: Fri Sep 25, 2015 3:00 am

### Help with Self test 9.4A

Hi, self test 9.4A asks to calculate the change in entropy from 20.00 bar to 5.00 bar. Why do we ignore the bar in our calculation and continue to use the gas constant 8.314 J /K*mol instead of the .08314 L. bar/K*mol?

Chem_Mod
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### Re: Help with Self test 9.4A

The units within the ln() term cancel, so you just need the number of moles and the ideal gas constant in J/mol*k to get the right units.