Using Pb-Sn eutectic phase diagram answer following questions:

a) Calculate the Henryian activity coefficient of Pb and Sn at the solubility limit at 150 ^oC

b) Draw activity of Pb and Sn vs. mol fraction of X_Sn at 150 ^oC

c) Calculate molar Gibbs free energy of mixing of solid solution at solubility limits at 150^oC

d) Plot schematically DG^m vs. X_Sn curve for solid and liquid solution at 150 ^oC. Use atomic %! X_Sn=at%/100!