-22.1
Assume that all gases are perfect and that data refer to 298.15 K unless otherwise stated. Calculate $\Delta S$ (for the system) when the state of $3.00 \mathrm{~mol}$ of perfect gas atoms, for which $C_{p, \mathrm{~m}}=\frac{5}{2} R$, is changed from $25^{\circ} \mathrm{C}$ and 1.00 atm to $125^{\circ} \mathrm{C}$ and $5.00 \mathrm{~atm}$. How do you rationalize the $\operatorname{sign}$ of $\Delta S$?