Figure $1$: Copper $-$ Silver Phase Diagrams

Composition $($at$\%$ Ag$)$

$($Cu$)$

Composition $($wt$\%$ Ag$)$

$($Ag$)$

$1$

Q$2.$ Interpretation of Phase Diagrams $(10\%)$

Is it possible to have a copper$-$silver alloy that, at equilibrium, consists of a $$ phase of composition $92wt\%Ag-8wt\%Cu$ and also a liquid phase of composition $76wt\%Ag-24wt\%Cu?$

If so$,$ what will be the approximate temperature of the alloy?

If this is not possible, explain why.

Q$3.$ Interpretation of Phase Diagrams $(15\%)$

A copper$-$silver alloy is heated to $900C$ and is found to consist of $$ and liquid phases. If the mass fraction of the liquid phase is $0\mathrm{.}68,$ determine

$($a$)$ the composition of both phases, in both weight percent and atom percent, and