5. A copper-nickel alloy of composition 70 wt\% Ni-30 wt\% Cu is slowly heated from a temperature of 1300C. (a) At what temperature does the first liquid phase form? (b What is the composition of this first liquid phase? (c) At what temperature does complete melting of the alloy occur? (d) What is the composition of the last solid remaining prior to complete melting? Figure 10.3 on page 387 is given below