The pressure-volume work for an ideal gas can be v, calculated by using the expression $w=-{\int }_{v_i}^{v_f} p_{ex}dV$

 The work can also be calculated from the p V, plot by using the area under the curve within the specified limits. When an ideal gas is compressed (a) reversibly or (b) irreversibly from volume ${\mathrm{V}}_{\mathrm{i}}$ to ${\mathrm{V}}_{\mathrm{f}}$ choose the correct option :

The P-V curve's area under represents work done. The area under the PV curve for irreversible compression of the gas is greater than the area under the curve for reversible compression, as can be seen in the curve above.
As a result, more work is required for irreversible compression than for reversible compression.

$w_{\text{irrev }}>w_{\text{rev }}$ (always)