Work, reversible and irreversible

$\Delta U=q+w$

Ethan-Van To Dis2L
Posts: 50
Joined: Fri Sep 29, 2017 7:05 am

Work, reversible and irreversible

So I was looking at Example 8.5 and it said that we should expect the work from a irreversible reaction to be less than that of a reversible reaction. Can someone explain to me why that is?

kaushalrao2H
Posts: 63
Joined: Thu Jul 13, 2017 3:00 am
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Re: Work, reversible and irreversible

in reversible expansion, the maximum amount of work is being done by the system because external pressure remains equal to the internal pressure as the gas expands. in irreversible expansion, the external pressure is constant and work is not maximized.

Janine Chan 2K
Posts: 71
Joined: Fri Sep 29, 2017 7:04 am

Re: Work, reversible and irreversible

Also, in reversible expansion, the external pressure always matches the internal pressure. If there is any increase in pressure, external and internal energy will match each other. So, reversible reactions are always doing the maximum possible amount of work. In a reversible reaction, the process is completed very quickly, and external and internal pressure do not match each other at all times. This implies that the maximum amount of work possible is not being done.