An ideal gas is allowed to expand against a constant pressure of 2 bar from 10 L to 50 L in one step. The amount of work done by the gas is x. if the same expansion were carried out reversible, what is the relation of work done with the earlier case?

Explanation

In the first case, as the expansions is against constant external pressure
`W = -rho_("ext")(V_(2)-V_(1)) = -2bars xx (50-10)` L
`=-80 L bar` (1 L bar = 100 J)
`=-80 xx 100 J = -9 kJ`
If the given expansion was carried out reversibly, the internal pressure of the gas should be greater than the external pressure at every state. Hence, the work done will be more.