A 1.5-kg specimen of a 88wt% Pb-12wt% Sn alloy (Animated Figure 9.8) is heated to 220°C; at this temperature it is entirely an alpha-phase solid solution. The alloy is to be melted to the extent that 50% of the specimen is liquid, the remainder being the alpha-phase. This may be accomplished either by heating the alloy or changing its composition while holding the temperature constant.
a) To what temperature must the specimen be heated? Answer in°C.
b) How much tin must be added to the 1.5-kg specimen at 250°C to achieve this state? Answer in kg.