Electromotive-force measurements were made on the cell:Pt|H2(g,p = 101.325 k Pa)|HBr(mA), SrBr2(mB)|AgBr(s)|Ag(s). Activity coefficients of HBr in (hydrogen bromide + strontium bromide)(aq) were determined from electromotive-force measurements at temperatures ranging from 278.15 K to 318.15 K at 10 K intervals and at constant total ionic strengths of (0.1, 0.25, 0.5, 1.0, 2.0, and 3.0) mol · kg-1. The results have been interpreted using Harned's empirical equations and also the comprehensive treatment of Pitzer. Activity coefficients for HBr in the salt mixture follow Harned's rule only at I = 0.1 mol · kg-1. At higher ionic strengths, the eperimental results are best described by a non-linear equation. The Pitzer mixing parameters SΘH.Sr and ΨH.Sr.Br (including higher-order electrostatic effects) and ΘH.Sr and ΨH.Sr.Br (excluding higher-order effects) as well as the temperature derivatives of the mixing coefficients have been determined and compared with the results for similar mixtures. The activity coefficients and excess enthalpies for HBr and SrBr2 have also been calculated at the experimental temperatures and compared with the results of other investigators.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Physical and Theoretical Chemistry