Equilibrium partial pressures of strong acids over concentrated saline solutions-I. HNO3

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)22_Publication in policy or professional journal

47 Scopus Citations
View graph of relations


  • S. L. Clegg
  • P. Brimblecombe


Original languageEnglish
Pages (from-to)91-100
Journal / PublicationAtmospheric Environment (1967)
Issue number1
Publication statusPublished - 1988
Externally publishedYes


Equilibrium partial pressures of HNO3 have been measured at 25°C over concentrated aqueous solutions containing the ions H+, NO3 -, SO4 2-, K+, NH4 + and Mg2+. Measurements agree closely with predictions made using a Henry's Law constant of 2.45 × 106 mol2 kg-2 atm -1 for the reaction HNO3(g) = H(aq.) + + NO3(aq.) -, and the Pitzer activity coefficient model. The model is recommended for the calculation of solute and solvent activities in aqueous aerosols at high ionic strength, corresponding to equilibrium relative humidities greater than about 70 %. The following new parameters have been estimated for the model using the partial pressure measurements and other thermodynamic data: ψH,Na, NO, -0.003; θ3 NO, 0.0926; ψ3,SO4 NO, -0.0046; ψ3,SO4,KNO, 0.0066; ψ3,SO4,NaH,NH, -0.01; ψ4,NO3 H,K,No, -0.01. © 1988.33

Research Area(s)

  • activity coefficient, Aerosols, Henry's Law, nitric acid, partial pressure, Pitzer model, saline solutions, solubility