The reaction
N₂(g) + 3 H₂(g) → 2 NH₃(g)
has a measured standard Gibbs free energy change of −32.9 kJ at 298 K.
Given that the standard Gibbs free energies of formation of N₂(g) and H₂(g) are zero, determine the standard Gibbs free energy of formation of NH₃(g) in kJ mol⁻¹. Report the value to one decimal place.