Q$2(35$ Points$)$ An insulated rigid tank initially contains $1\mathrm{.}4-$kg saturated liquid water and water vapour at $200C.$ At this state, $25$ percent of the volume is occupied by liquid water and the rest by vapour. Now an electric resistor placed in the tank is turned on doing electric work on the water. After a certain period of time the water in the tank becomes saturated water vapour completely. Determine;

a$)$ The volume of the tank,

b$)$ The final temperature,

c$)$ The amount of work done during the process.

Note: You may neglect the mass of saturated water vapour at the initial state.