A sensor for the in situ determination of acidity levels in concentrated sulfuric acid

A potentiometric method at imposed weak current between two paste electrode s, ferrocene and chloranil, permits the in situ determination of sulfuric a cid concentrations (0.5-11.0 M). The different factors affecting the potent ial at imposed current as current intensity, temperature and H+ ion concent ration are studied. The potentials measured between ferrocene and chloranil electrodes are directly linked to the acid concentration. The acidity R-i( H) function, which represents the determination of the H+ activity has been determined and compared to Strehlow R-o(H), Janata H-GF and Hammer H-o fun ctions. R-i(H) is numerically equal to the thermodynamic R-o(H).