Experimental vapour$-$liquid equilibrium data for a binary at a constant pressure of $101\mathrm{.}3$kPa, are plotted in the figure below.

at a constant pressure of $101\mathrm{.}3$kPa, are plotted in the figure below.

$($a$)$ Label, on the plot, all important regions and points. Show the azeotropic mixture conditions.

$($b$)$ What are the boiling temperatures of Components $\text{'}$A$\text{'}$ and $\text{'}B\text{'}$ at $101\mathrm{.}3$kPa $?A=55C,B=100C$

$($c$)$ A sample, consisting of $14$kmol of $\text{'}$A$\text{'}$ and $6$kmol of $\text{'}$B$\text{'},$ is heated $($while holding the pressure constant at $101\mathrm{.}3$kPa $)$ from a starting temperature of $85C.$ At the following conditions, specify the moles and composition of each phase present.

$($i$)$ Initially?

$($ii$)$ The temperature at which a new phase first appears?

$($iii$)$ At $105C?$

$($iv$)$ At $125C?$