You are tasked with designing a flash drum to remove unreacted ethylene from $1,2-$dichloroethane so the ethylene can be recycled to the reactor. $90mo\frac{l}{s}$ of a vapor mixture of $80$mol$\%1,2-$dichloroethane $($DCE$)$ and $20$mol$\%$ ethylene $($E$)$ at $450K$ is to be flashed from $5$ bar to $2$ bar and $298K.$ You determine that the product vapor flowrate is $18\mathrm{.}8mo\frac{l}{s}$ with a composition of $95\mathrm{.}4$mol$\%E$ and the product liquid flowrate is $71\mathrm{.}2mo\frac{l}{s}$ with a composition of $99\mathrm{.}9$mol$\%$ DCE. Calculate the energy requirement using the vapor product stream for a reference state. You cannot ignore pressure change contributions in the energy balance.

a$.$ What are the specific enthalpies for each stream $(k\frac{J}{m}ol)?$ :

b$.$ What is the enthalpy of each stream $(k\frac{J}{s})?$

c$.$ What is the heating$/$cooling requirement $(Q)$ for this separator $(k\frac{J}{s})?$