1. In the table on the following page are excess Gibbs energy of mixing data for three liquid solution phases at various temperatures and compositions (units: Joules/mol). Using these data, determine

for each system whether the data are best fitted by a regular solution model, a subregular solution model, a sub-subregular solution model. In each case, give the coefficients determined from your fitting, using Au, Ti and Zn, respectively as element B.