The hygroscopicity and acidity of ambient aerosols are key intensive properties. They have a strong impact on the chemistry and physics of the aerosol (e.g. phase state and viscosity). They control the gas-particle partitioning of inorganic nitrogen and chlorine, and of some organic components such as glyoxal. Both aerosol water content (LWC) and acidity (i.e. aerosol pH) influence the kinetics and thermodynamics of many heterogeneous and aqueous-phase chemical processes in the atmosphere. An accurate knowledge of these quantities is key to understanding aerosol chemical regimes in a particular region. Both LWC and pH can be measured directly with specialized instrumentation, but particularly for pH such instrumentation is still not yet suitable for rapid field measurements. Therefore, thermodynamic models are typically used to predict pH and water content based on a combination of aerosol and gas measurements. The NASA ASIA-AQ aircraft mission targeted several major east Asian urban areas (Manila, Seoul, Taiwan and Bangkok) during Feb/March, 2024, as well as Northern Thailand during the burning season. Unlike many previous aircraft campaigns, all relevant inorganic species that comprise the NHx, NOy and Cly equilibria in the gas and particle phase are not only fully constrained by measurements, but often with significant redundancy. This work uses the recently released open-source package AMATI (AMbient Aerosol Thermodynamic calculator in Igor) to run the E-AIM model (Extended Aerosol Thermodynamics Model), specifically Model IV. Based on the ability of E-AIM to reproduce the measured partitioning of NHx, NOy and Cly in ASIA-AQ within uncertainties, we show that: (1) Strong acidity gradients often exist at the urban/remote interface that affect pollutant transport and PM lifetime; (2) In concentrated urban plumes, there is evidence in this dataset for LWC promoting both OOA and sulfate formation.(3) In smoky conditions, the contributions of the organic fraction to both LWC and pH are non-negligible, and several approaches are presented to improve modeling of these plumes (4) As expected, in the urban plume NH3 measurement uncertainties have the largest impact upon model skill, and hence our ability to predict pH accurately