$1.-$ Storage tanks, especially those used to store hydrocarbons, have an inert atmosphere. Which is achieved by injecting carbon dioxide or nitrogen, which prevents explosive vapors from accumulating on the liquid, as shown in the figure.Develop a model of the system, where the gas pressure $($P$)$ and the liquid volume $($Vl$)$ are your variables of interest. The inlet and outlet gas molar flows are represented by qf and q$,$ respectively. While Fr and F represent the volumetric inlet and outlet flows of the liquid. Assume that the volume, VT$,$ of the tank is constant.