$1\mathrm{.}18.$ Two $kg$ of water exist initially as a vapor and liquid at $90C$ in a rigid

container of volume $2\mathrm{.}42m^3.$

a$.$ At what pressure is the system?

b$.$ What is the quality of the system?

c$.$ The temperature of the container is raised to $100C.$ What is the quality of the system, and what is the pressure? What are $H_{?}$ and $U_{?}$ at this point relative to the initial state?

d$.$ As the temperature is increased, at what temperature and pressure does the container contain only saturated vapor?

What is $H_{?}$ and $U_{?}$ at this point relative to the initial state?

e$.$ Make a qualitative sketch of parts $($a$)$ through $($d$)$ on a $P-V$ diagram, showing the phase envelope.