M$4$b$.$I$1$

A gas mixture containing $85\mathrm{.}0$mol$\%N_2$ and the balance $n-$hexane flows through a pipe at a rate of $100\mathrm{.}0\frac{m^3}{h}.$ The pressure gauge displays $1\mathrm{.}00$atm and the temperature is $100C.$

$($a$)$ Is the gas saturated? If not, to what temperature $(C)$ would it have to be cooled at constant pressure in order to begin condensing hexane?

$($b$)$ To what temperature $(C)$ would the gas to be cooled at constant pressure in order to condense $80\%$ of the hexane?