%A Zhao Kaiyuan; Lei Hongyi
%T DETERMINATION OF MEAN ACTIVITY COEFFICIENTS OF HYDROCHLORIC ACID IN CONCENTRATED SOLUTIONS UP TO 15 *m* WITH GLASS ELECTRODE
%0 Journal Article
%D 1986
%J Acta Physico-Chimica Sinica
%R 10.3866/PKU.WHXB19860105
%P 30-36
%V 2
%N 01
%U {http://www.whxb.pku.edu.cn/CN/abstract/article_21786.shtml}
%8 1986-02-15
%X Mean activity Coefficients of HCl in concentrated hydrochloric acid solutions are determined by measuring emf′s of following cells (A). Ag-AgCl/HCl(m)/H_2(P)/Pt(black) (B). Ag-AgCl/HCl(m)/pH-glass electrode for HCl molalities from 0.01844 to 15.02 tool kg~(-1) at 25 ℃. Using observed emf data of ceils (A) and (B), mean activity coefficients of HCl are calculated, and their deviations are less than 1.2%. Within this molality range, “standard potential” E_G~0 of pH-glass electrode is a constant and its standard deviation is equal to 0.016%. The pH-glass electrode used has good reproducibility. Therefore, it is possible to determine the activity coefficients in high concentrated hydrochloric acid solution by using pH-glass electrode.

For concentrated hydrochloric acid in molality range 0.1844—15.02 mol kg~(-1) at 25 ℃, the lograrithm of activity coefficients of HCl can be expressed adquately by the equation:

logγ±=-0.5115/(1+1.471)+0.1069 m+7.412×10~(-3) m-6.637×10~(-4) m~3

+1.586×10~(-5) m~4

where m is the HCl concentration in molality, γ± is its activity coefficients. Using this equation, activities of solvent H_2O have been calculated.