Question

Thermodynamics Question

A Joule expansion refers to the expansion of a gas from volume
*V*_{1} to volume *V*_{2}against no
applied pressure, and is sometimes also called a free expansion.
There is no work done, because the *P* of -*PdV* is
zero. By insulating the system, this process can be done
adiabatically, so there is no change in heat. For an ideal gas, the
adiabatic process is also isothermal, so there is no change in
thermodynamic energy, ∆*U* = 0 (which is not surprising,
since both *q* and *w* are 0). Because entropy is a
state variable, the change of the system's entropy can be
calculated using the most convenient means possible, which would be
through a reversible process, and is just given by the usual
expression for a reversible isothermal expansion, ∆*S*=
*nR* ln(*V*_{2}/*V*_{1}).
Thus, even though there is no heat flow, there is certainly an
increase in entropy of the system.

Explain how this overall result is consistent with the 2nd Law of Thermodynamics. Is this process reversible or irreversible? Explain your reasoning.

Answer #1

A Joule expansion refers to the expansion of a gas from volume
V1 to volume V2 against no
applied pressure, and is sometimes also called a free expansion.
There is no work done, because the P of -PdV is
zero. By insulating the system, this process can be done
adiabatically, so there is no change in heat. For an ideal gas, the
adiabatic process is also isothermal, so there is no change in
thermodynamic energy, ∆U = 0 (which is...

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(2) the work done by the system,
(3) the heat entering thesystem,
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b.- A reversible adiabatic expansion to a pressure of 10
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Calculate the change in entropy for one mole of ideal gas which
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