Equilibrium and structural studies of silicon(iv) and aluminium(iii) in aqueous solution. V. Acidity constants of silicic acid and the ionic product of water in the medium range 0.05–2.0 M Na(CI) at 25°C

Methyl‐Hydroxypyridinecarboxylic Acids as Possible Bidentate Chelating Agents for Aluminium(III): Synthesis and Metal–Ligand Solution Chemistry

“…As a check of the accuracy of the entire experimental system, the pK w value for water in (Na)Cl 0.6 m was computed from HCl + NaOH titrations. The values obtained from two different series of experiments (pK w = 13.719 ± 0.002 and pK w = 13.710 ± 0.002) compare well with the literature value [31] in NaCl 0.6  at 25°C (13.727 ± 0.001).…”

Benzenecarboxylate Surface Complexation at the Goethite (α-FeOOH)/Water Interface

“…From Eq. [13], larger values of C 2 (smaller values of C 1 ) decrease the apparent formation constant. This effect is illustrated in Fig.…”

“…From Eq. [6], the apparent formation constant, β 2,2,1 (app) , for this species is given by ln β 2,1,1 (app) = ln β 2,2,1 (int) − 2.0F 0 RT + 2.0F 1 RT , [13] as z 0 = 2.0 and z 1 = −2.0, 0 and 1 are always positive with 0 > 1 . In the absence of electrostatic contributions to the calculations (i.e., z 0 = z 1 = 0), the speciation of the 2,2,1 species, given by the full lines in Fig.…”

“…All potentiometric titration data are presented in terms of Z B as a function of pH, ] is the total concentration of the triply-coordinated site on the {110} plane, H is the total proton concentration (mol/L) relative to the defined zero proton level, [H + ] is the free proton concentration, and K w is the ionic product of water in 0.1 M NaNO 3 (13). The titration curves for the H -Benzenecarboxylate-≡FeOH system in the 37 and 43 m 2 /g goethites are shown in Figs.…”

Comparison of the Adsorption ofo-Phthalate on Boehmite (γ-AlOOH), Aged γ-Al2O3, and Goethite (α-FeOOH)

“…In the evaluation of equilibrium models for the phthalate adsorption on the metal (hydr)oxide surfaces, previously determined equilibrium constants for the binary systems H ϩ -'MeOH (30,33,34) and H ϩ -hydrogen phthalate (5), were regarded as known. For the autoprotolysis of water, the equilibrium constant log K W ϭ Ϫ13.775 was used (36). The stoichiometric compositions of the species forming at the solution-mineral interfaces, and corresponding equilibrium constants describing their formation, were evaluated using the computer program FITEQL, version 2.0 (37).…”