Gas phase dissociation of H2SO4: a computational study

The decomposition of gaseous sulfuric acid has been investigated computationally. In particular the role of the hydrated gaseous coordination adducts of SO3(g) and H2SO4(g) in the (dissociation + decomposition) process has been evaluated. A first principles study of the gaseous coordination complexes SO3(H2O)n (n = 1 to 3) and H2SO4(H2O)m (m = 1 to 2) has been carried out deriving equilibrium ground state structures, vibrational frequencies and energetic stabilities by the Moller–Plesset perturbation approximation. These results have been used to derive the enthalpy of formation at 0 K and the Gibbs energy functions of these molecules. A new thermodynamic modeling of the decomposition of H2SO4(g) has been therefore performed considering the effect of temperature, pressure and initial composition of the gas (hydration conditions).