Assume all gases are perfect unless stated otherwise. Note that 1 atm = 1.013 25 bar. Unless otherwise stated, thermochemical data are for 298.15 K. Take nitrogen to be a van der Waals gas with $a=1.352 \mathrm{dm}^6 \mathrm{~atm} \mathrm{\textrm {mol } ^ { - 2 }}$ and $b=0.0387 \mathrm{dm}^3 \mathrm{~mol}^{-1}$, and calculate $\Delta H_{\mathrm{m}}$ when the pressure on the gas is decreased from $500 \mathrm{~atm}$ to $1.00 \mathrm{~atm}$ at $300 \mathrm{~K}$. For a van der Waals gas, $\mu=\{(2 a / R T)-b\} / C_{p, \mathrm{~m}}$. Assume $C_{p, \mathrm{~m}}=\frac{7}{2} R$.
+3.60