Question

Calculate the Gibbs free energy change (ΔG) for the reaction:N2(g) + 3H2(g) ⇌ 2NH3(g)Given the standard Gibbs free energy of formation (ΔG°f) values at 298 K are:ΔG°f of NH3(g) = -16.6 kJ/molΔG°f of N2(g) = 0 kJ/molΔG°f of H2(g) = 0 kJ/molAssume ideal gas behavior for all gases involved in the reaction.

Answer 1

To calculate the Gibbs free energy change  G  for the reaction, we can use the following equation:G = Gf products  - Gf reactants For the given reaction:N2 g  + 3H2 g   2NH3 g The products are 2 moles of NH3 g  and the reactants are 1 mole of N2 g  and 3 moles of H2 g . Using the given standard Gibbs free energy of formation  Gf  values, we can calculate G:G = [2 * Gf NH3 ] - [Gf N2  + 3 * Gf H2 ]G = [2 *  -16.6 kJ/mol ] - [0 kJ/mol + 3 * 0 kJ/mol]G =  -33.2 kJ/mol  - 0G = -33.2 kJ/molSo, the Gibbs free energy change  G  for the reaction is -33.2 kJ/mol.