$4.-$ A tank whose volume is $0\mathrm{.}01m^3$ is initially evacuated. A pinhole develops in the wall,

and air from the surroundings at $21C,1$ bar enters until the pressure in the tank is $1$ bar.

If the final temperature of the air in the tank is $21C,$ determine:

a$)$ the final mass in the tank, in $g.$

b$)$ the heat transfer between the tank contents and the surroundings, in kJ $.$