The Second Dissociation Constant of Sulfuric Acid at Elevated Temperatures from Potentiometric Measurements

Abstract

The second dissociation constant of sulfuric acid in 1 m KCl media has been determined from 25 to 200 °C using Debye–Hückel equation from the data on the electromotive force of a hydrogen ion-concentration cell. The thermodynamic values for the HSO4−=H++SO42− reaction and the KSO4− ion-pair association constant are also presented.

Dissociation constants and speciation in aqueous Li2SO4 and K2SO4 from measurements of electrical conductance to 673K and 29MPa

“…The agreement is excellent. Matsushima and Okuwaki (1988) reported the 2nd dissociation constant of K 2 SO 4 found from potentiometric measurements at temperatures 298 up to 473 K at water densities from 860 to 1000 kg m À3 . Their results are above our log K K Eq.…”

“…The initial and final dates of their K 2 SO 4 experiments are March 14, 1904, andSeptember 29, 1905, respectively. These investigations were continued at ambient temperatures by different authors (Clews, 1935;Jenkins and Monk, 1950;Broadwater and Evans, 1974;Valyashko and Ivanov, 1974;Fedoroff, 1989;Indelli, 1989) and at elevated temperatures (Quist and Marshall, 1966) using conductance measurements, and (Matsushima and Okuwaki, 1988) using e.m.f. measurements.…”

Thermodynamics of the ZnSO4-H2SO4-H2O system

“…Heat capacity functions for H2O and SO4 2--and HSO4 --ions were taken from literature [50,51]. The selected thermodynamic functions for the sulfate species correspond to the Okuwaki K2-equation [52].…”

“…Pitzer parameters for the Zn 2+ -HSO4binary were optimised using available solubility data of heptahydrate and hexahydrate [20] and boiling point data [26] of the ternary ZnSO4-H2SO4-H2O system. Pitzer parameters for the H2SO4-H2O -system were taken from Sippola [59], the chosen parametrisation corresponds to Okuwaki K2-equation [52] and parameter set A in Sippola's paper.…”

Methodology optimization for the analysis of phenolic compounds in chestnut (Castanea sativaMill.)

“…These good chromatographic results may be due to the use of H 2 SO 4 . SO 4 2− plays an important role in the precipitation of inorganic compounds at elevated temperatures, and its maximum heat capacity is around 80 ℃ (Matsushima and Okuwaki, 1988). The absence of O 2 in the methanolysis reaction was also important, since in this way, unwanted oxidations are avoided (Hartzfeld et al., 2002).…”