homework 8.27

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Miya Eberlein 1J
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homework 8.27

Postby Miya Eberlein 1J » Sun Jan 10, 2016 4:08 pm

In question 8.27 we're presented with two different pressures, one from the calibration of a piston and the other for an irreversible expansion. When solving for work done for both reversible and irreversible expansions, how do we know when to use which pressure?

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Re: homework 8.27

Postby Chem_Mod » Mon Jan 11, 2016 1:50 am

For the reversible expansion, use the formula w=-nRTln(V2/V1). The initial pressure P=1.79 atm is given just so you can find the moles n using PV=nRT

For the irreversible expansion, the external pressure is given as held at 1 atm, and w = -Pext*deltaV.

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