A NiO-20 mol% MgO ceramic is heated to 2200°C. Determine 

(a) The composition of the solid and liquid phases in both mol% and wt%; 

(b) The amount of each phase in mol% and wt%; and 

(c) Assuming that the density of the solid is 6.32 g/cm³ and that of the liquid is 7.14 g/cm³, determine the amount of each phase in vol%.