THE ACTIVITY-COEFFICIENTS OF HCL IN HCL-NA2SO4 SOLUTIONS FROM 0 TO 50-DEGREES-C AND IONIC STRENGTHS UP TO 6 MOLAL

The electromotive force of HCl-Na2SO4 solutions has been determined fr om 5 to 50 degrees C and ionic strengths from 0.5 to 6m with a Harned type cell Pt; H-2(g, 1 atm)\HCl(m(1)) + Na2SO4(m(2))\AgCl, Ag The resu lts have been used to determine the activity coefficient of HCl in the mixtures. The activity coefficients have been analyzed with the Fitte r equations to account for the ionic interactions. The measurements we re used to determine interaction coefficients (beta(0), beta(1))for Na HSO4 solutions from 5 to 50 degrees C. The model represents the mean a ctivity coefficients of HCl in the mixtures to +/-0.005 over the entir e temperature and concentration range of the measurements. The results have been combined with literature data to provide parameters that ar e valid from 0 to 250 degrees C for NaHSO4 solutions.