EXERCISE $20.$ An immiscible liquid$-$liquid binary system contains A and $B$ components at ambient temperature. The data resulted of a series of experiments gave the values of the mixing temperature versus the mole fraction of $A$ in the mixture.

$\backslash$table$[[x_A,0\mathrm{.}1,0\mathrm{.}2,0\mathrm{.}3,0\mathrm{.}5,0\mathrm{.}7,0\mathrm{.}8,0\mathrm{.}9]]$

$\backslash$table$[[T(C),30,50,60,70,63,57,45]]$

A$)$ Draw the curves corresponding to the binary diagram liquid$-$liquid.

B$)$ Indicate on the diagram the different zones $($Miscible$,$ immiscible on the phase diagram

C$)$ What is the temperature limit to make an immiscible mixture in a miscible mixture if the mole fraction of $A$ is $0\mathrm{.}25$ mole?

Temperature $(C)$