The solubility of oxygen has been measured in a number of electrolytes [(LiCl, KCl, RbCl, CsCl, NaF, NaBr, NaI, NaNO3, KBr, KI, KNO 3, CaCl2, SrCl2, BaCl2, Li 2SO4, K2SO4, Mn(NO3) 3)] as a function of concentration at 25°C. The solubilities, μmol (kg-H2O)-1, have been fitted to a function of the molality m (standard deviation σ < 3μmol-kg-1) ln([O 2]0/[O2]) = lnγ(O2) = Am + Bm2 where A and B are adjustable parameters and the activity coefficient of oxygen γ (O2) = [O2] 0/[O2]. The limiting salting coefficient, kS = (∂lnγ/∂m)m=0 = A, was determined for all salts. The salting coefficients for the chlorides and sodium salts showed a near linear correlation with the crystal molar volume Vcryst = 2.52 r 3. The salting coefficients determined from the Scaled Particle Theory were in reasonable agreement with the measured values. The activity coefficients of oxygen in the solutions have been interpreted using the Pitzer equation (Equation Presented) where λO2i is a parameter that accounts for the interaction of O2 with cations (c) and anions (a) with molalities ma and mc, and ζO2ca accounts for interactions for O2 with the cation and anion pair (c-a). The ζO2i and ζO2ca coefficients determined for the most of the ions are in reasonable agreement with the tabulations of Clegg and Brimblecombe. The values λO2i for most of the ions are a linear function of the electrostriction molar volume (Velect = V0 - Vcryst).
- Activity coefficient
- Alkali and alkaline earth chlorides
ASJC Scopus subject areas
- Molecular Biology
- Physical and Theoretical Chemistry