$(13\%)$ Saturated liquid water at $580K$ is partially evaporated by passing it through a throttling valve until it reaches $0\mathrm{.}01$ bar.

$($a$)(3\%)$ On the $T-S$ diagram $($next page$),$ mark the process with an arrow, labeling the initial state $"1"$ and the final state $"2".$

$($b$)(5\%)$ Estimate the quality of the water$/$steam mix at the end of the process. For better accuracy, you must use the lever rule instead of interpolating between the iso$-$lines.

$($c$)(5\%)$ Estimate the molar Helmholtz energy change of vaporization, $A^{\text{v}\text{a}\text{p}},$ at $0\mathrm{.}01$ bar $($in $k\frac{J}{m}ol.$ The molar mass of water is $18\frac{g}{m}ol.$