Question

Calculate the Gibbs free energy change (ΔG) for the following chemical reaction at 25°C and constant pressure of 1 atm:2H2(g) + O2(g) → 2H2O(l)Given the following standard Gibbs free energy of formation values (ΔfG°) at 25°C:H2(g) = 0 kJ/molO2(g) = 0 kJ/molH2O(l) = -237 kJ/mol

Answer 1

To calculate the Gibbs free energy change  G  for the reaction, we can use the following equation:G =  fG products  -  fG reactants For the given reaction:2H2 g  + O2 g   2H2O l The fG values are:H2 g  = 0 kJ/molO2 g  = 0 kJ/molH2O l  = -237 kJ/molNow, we can plug these values into the equation:G = [2   -237 kJ/mol ] - [2   0 kJ/mol  + 1   0 kJ/mol ]G =  -474 kJ  -  0 kJ G = -474 kJSo, the Gibbs free energy change  G  for the reaction at 25C and constant pressure of 1 atm is -474 kJ.