Thermodynamic Equilibrium Properties of Aqueous Solutions of Nitrate, Sulfate and Ammonium

Abstract

Knowledge of the thermodynamic equilibrium properties of aqueous solutions is required in virtually any calculation associated with particle and droplet acidification. For example, prediction of the equilibrium vapor pressures of dissolved solutes and water is necessary when predicting the rate of uptake of pollutant gases into cloud- and raindrops and aerosol particles. In addition, evidence indicates that atmospheric aerosols and small droplets are frequently in chemical equilibrium with the local surrounding air. In such a situation, given the ambient gaseous concentrations of pollutant species, and the temperature and relative humidity, it is desired to determine the physical state (liquid or solid) and the chemical composition of the particle or drop in equilibrium with the air.