Composition of aqueous solutions of ammonium sulphate and sulphuric acid

Abstract

Concentrations of SO^2–₄ and HSO^–₄ anions in aqueous solutions of ammonium sulphate and sulphuric acid have been determined by means of Raman spectroscopy. The molar ratio P₀=m_H2SO4/m(_NH4)2SO4 and the total molality m_T were in the range 1.0–2.5 and 3.38–18.21 mol kg^–1, respectively. The results obtained have been used to establish the dependences of the stoichiometric dissociation quotient Q_m=m_H⁺m_SO^–4/m_HSO^–4 and of the fraction α of total sulphate on the molar ratio P₀ and the total molality m_T of the solution at 20 °C.