(a) Show that for steady flow process, \(\Delta H=Q-W_{\mathrm{S}}\).

(b) One mole of air, initially at \(423.15 \mathrm{~K}\left(150^{\circ} \mathrm{C}\right)\) and \(8 \mathrm{bar}\), undergoes the following mechanically reversible changes: It expands isothermally to a pressure such that when it is cooled at constant volume to \(323.15 \mathrm{~K}\left(50^{\circ} \mathrm{C}\right)\), its final pressure is \(3 \mathrm{bar}\). Assuming air to be an ideal gas for which \(C_{P}=7 / 2 R\) and \(C_{V}=5 / 2 R\), calculate \(W\), \(Q, \Delta U\) and \(\Delta H\).