A binary mixture of species a and b behaves as an ideal gas at 300 K and 1 bar. Calculate the partial molar Gibbs energy of species a, Ga, and the total solution Gibbs energy, g, at the following compositions. The pure species Gibbs energy for species a is 225 kJ/mol and for species b is 240 kJ/mol.

(a) At ya = 1

(b) At ya = 0.5

(c) At “infi nite dilution”