What are the things must be remember while studying adiabatic processes?

1 Answer
Aug 18, 2017

Well, it's always important to remember the definition of an adiabatic process:

#q = 0#,

So, there is no heat flow in or out (the system is thermally insulated from the surroundings).

From the first law of thermodynamics:

#DeltaE = q + w = q - intPdV#

where #w# is the work from the perspective of the system and #DeltaE# is the change in internal energy.

For an adiabatic process, we then have #ul(DeltaE = w)#, so if the system expands, the internal energy of the system decreases as a direct result of the expansion work only.

From the second law of thermodynamics:

#DeltaS >= q/T#

where #># corresponds to irreversible processes and #=# corresponds to reversible processes.

If there is absolutely no heat flow in or out, the system entropy should be constant, as long as the process is reversible. [You can read more about reversible processes here.](https://socratic.org/questions/why-does-the-entropy-is-defined-by-q-reversible-what-is-the-meaning-of-defining-)