Question

In thermodynamics, what is the difference between a reversible and irreversible isothermal expansion/compression? Also, I'm confused when the question gives a certain process to be irreversible/reversible, what hint is it talking about? (like which variable becomes constant?)

Answer 1

1)reversible isothermal expansion/compression process are always quasistic.if process that is not reversible is called irreversible. Joule unit expansion is irreversible because initially the system is not uniform

2)A reversible adiabatic process is called definitely isentropic but an isentropic process need not necessarily be reversible adiabatic but it is adiabatic definitely..this this most important difference between reversible and irreversible isothermal

3)Irreversible isothermal compression:

$\Delta$E=q+w.............(1)

where. reversible isothermal compression

$\Delta$E=0

4) we know that W_irr > W_rev

  W_irr=Irreversible isothermal compression:

W_rev=reversible isothermal compression

5)

The work done in an adiabatic reversible process is given by:

W=RΔT/(1−γ)

and

The work done in an irreversible process is given by:

W=PextΔV

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temperature variable becomes constant according to your question

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we can say that The reversible process is the ideal process which never occurs suddenly, while the irreversible process is the natural process that is commonly found in nature.Whereas when water evaporates, this can also be condensed in the form of rains this is natural evens so . This is a reversible process.