Standard enthalpy of vapourisation Δ_vap H^ for water at 100^° C is 40.66 kJmol^-1. The internal energy of vaporisation of water at 100^° C (in…

Standard enthalpy of vapourisation $\displaystyle \Delta_{\text {vap }} \mathrm{H}^{\ominus}$ for water at $\displaystyle 100^{\circ} \mathrm{C}$ is $\displaystyle 40.66 \mathrm{kJmol}^{-1}$. The internal energy of vaporisation of water at $\displaystyle 100^{\circ} \mathrm{C}$ (in $\displaystyle \mathrm{kJmol}^{-1}$ ) is : (Assume water vapour to behave like an ideal gas).