Module $12$ Lab$-$ Phase Diagrams I

$3-$ A copper$-$nickel alloy of composition $30wt\%Ni-70wt\%Cu$ alloy is slowly cooled from $1400C$ to $1150C.$

$($a$)$ At what temperature does the first solid phase form?

$($b$)$ What is the composition of this solid phase?

$($c$)$ At what temperature does the last of the liquid solidify?

$($d$)$ What is the composition of this last remaining liquid phase?