A piston$-$cylinder device initially contains $1\mathrm{.}0$ kg of water at $30C$ and $2$ MPa $.$ The water is heated at constant pressure until one$-$quarter of the mass evaporated. Determine:

a$)$ the initial volume of the system.

b$)$ the final volume and temperature after heating.

c$)$ the amount of heat added during the process $($in kJ $).$

d$)$ Show the process on T$-$u diagram.