Lisa found a phase diagram for magnesium (Mg)-lead (Pb) as given below. She has two samples in the oven at 400 °C with different compositions, (1) Mg 90wt%/Pb 10 wt%

and (2) Mg 10 wt%/Pb 90 wt%. At what temperature (•C), sample 2 will completely melt? Let's assume that the time is given enough for samples to be at the thermodynamic equilibrium.