Thermodynamics of Aqueous Sulfuric Acid up to 175 °C

Abstract

The potential of a lead amalgam-lead sulfate electrode has been measured relative to a hydrogen electrode in sulfuric acid at temperatures up to 175°C to obtain the standard reduction potential of the electrode and activity coefficients of sulfuric acid up to 0.2 molÁkg -1 . The resulting values are in agreement with earlier published values for 25 and 50°C and provide new results at elevated temperatures. It was found that the amalgam electrode was not stable in more concentrated acid, but it is suggested that the new results may be used to calibrate a more practical reference electrode system such as lead oxidelead sulfate for use in studies of more complex sulfate solutions at elevated temperatures and at higher acid concentrations.

Predictive models for the phase behaviour and solution properties of weak electrolytes: nitric, sulphuric, and carbonic acids

“…Activity of water at 298.15 K (left) and stoichiometric mean ionic activity coefficient of sulphuric acid at different temperatures (right) over the overall molality of sulphuric acid in aqueous solution. Continuous curves: SAFT-VRE Mie prediction, symbols: experimental data from the literature (left: circles96 , squares97 , triangles98 , right: circles 102 , squares103 ).…”