Questions 2 Calculate the Gibbs free energy for the reaction shown below at 25C (15 Marks) H2(g) + Cl2(g)-- 2 HCl (8) Given the data tabulated below: Substance Enthalpy Entropy H2(g) O kJ/mol + 131 J/mol Cl2(g) O kJ/mol + 223 J/mol -92 kJ/mol +187 J/molk HCI (g)