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Question
Graphically show the total work done in an expansion when the state of an ideal gas is changed reversibly and isothermally from \[\ce{(p_i, V_i)}\] to \[\ce{(p_f , V_f )}\]. With the help of a pV plot compare the work done in the above case with that carried out against a constant external pressure \[\ce{p_f}\].
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Solution
(i) Reversible Work is represented by the combined areas
and
(ii) Work against constant pressure, pf is represented by the area
Work (i) > Work (ii)
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