47. Solution to Chemistry Problem

11. Using the data from Table 1, construct a melting diagram for the silicon-gold system.
Table 1
Au,
% wt. 0 20 40 60 94 100
Тн, C 1420 1310 1160 905 370 1050
Тк, C 1420 370 370 370 370 1050

Where Тн is the crystallization onset temperature; Тк is the alloy crystallization end temperature.
Using the diagram for the 65% wt. Au alloy, determine:
1. Crystallization onset and end temperatures;
2. The composition of the first crystal and the last drop of liquid;
3. The mass of Si in the solid and liquid states upon cooling 1.5 kg of the alloy to 600 C.
Denote all areas and lines on the diagram and give the diagram a full title. Mark with dots the melts corresponding to 10 and 35% by weight of Au, which are in equilibrium with Si crystals.