Consider the phase diagram for a hypothetical A-B system. Assume that A and B form ideal solutions in the liquid state and in the solid state. a. If a solution containing 50 mol.\% B is cooled from 1300K, what is the composition of the first solid to form? What is the composition of the last liquid to solidify? b. For this 50 mol.\% B solution, estimate the fraction of solid and liquid in equilibrium at 1000K c. Sketch the activity-composition relationship for component B in the solution at 1300K,1100K and 800K. In each case state the standard state you have chosen