10.3 Al2O3, which melts at 2324 K, and Cr2O3, which melts at 2538 K form complete ranges of solid and liquid solutions. Assuming that ASCO₂ = AS, Al,O,, and that the solid and liquid solutions in the system Al2O3-Cr2O3 behave ideally, calculate 1. The temperature at which equilibrium melting begins when an alloy of X Al₂O₁ = 0.5 2. is heated, The composition of the melt which first forms, 3. The temperature at which equilibrium melting is complete, and 4. The composition of last-formed solid.