Question

Calculate the Gibbs free energy change at 25°C for the reaction:2NO(g) + O2(g) → 2NO2(g)Given the standard Gibbs free energy of formation at 25°C for NO(g), O2(g), and NO2(g) are +86.4 kJ/mol, 0 kJ/mol, and +51.3 kJ/mol, respectively.

Answer 1

To calculate the Gibbs free energy change  G  for the reaction at 25C, we can use the following equation:G =  Gf_products  -  Gf_reactants where Gf represents the standard Gibbs free energy of formation for each species involved in the reaction.For the given reaction:2NO g  + O2 g   2NO2 g The Gf values are:NO g : +86.4 kJ/molO2 g : 0 kJ/molNO2 g : +51.3 kJ/molNow, we can plug these values into the equation:G = [2   +51.3 kJ/mol ] - [2   +86.4 kJ/mol  + 0 kJ/mol]G =  +102.6 kJ  -  +172.8 kJ G = -70.2 kJSo, the Gibbs free energy change for the reaction at 25C is -70.2 kJ.