56. Solving a chemistry problem

16. Using the data in Table 1, plot the fusibility diagram of the Mg Ca system.
Table 1
Ca,
% wt. 0 10 20 40 52 70 79 90 100
Tn, C 650 600 520 670 710 600 440 710 800
Тк, C 650 520 520 520 710 440 440 440 800

Where Tn is the temperature of the beginning of crystallization; Тк is the temperature of the end of crystallization of the alloy.
According to the diagram for the alloy 65% wt. Ca define:
1. Temperatures of the beginning and end of crystallization;
2. The composition of the first crystal and the last drop of liquid;
3. The mass of Mg in the solid and liquid state when cooling 2.5 kg of the alloy to a temperature of 600 C.
On the diagram, mark all areas and lines, give the full name to the diagram. Determine the formula of a chemical compound.