Titration of bases in acetonitrile

The role of acids and bases on the electrochemical oxidation of hydroquinone: Hydrogen bonding interactions in acetonitrile

“…It has been observed that the presence of water does not influence the QH 2 voltammetric behaviour, however a strong acid as triflic acid (HTf) modifies importantly the oxidation pattern. After this, it was studied the effect of the presence of dimethylsulfoxide (DMSO) as solvent which possess a greater proton affinity than acetonitrile itself [26].…”

“…Higher concentrations of HTf and/or the passage of time, provokes even more the decrease of the anodic current of the reversible wave. Considering that concentrated solutions of strong acids are not very stable in acetonitrile [26], this behaviour suggests that degradation of hydroquinone could be happening and makes difficult a full characterization of the reversible wave. However, considering that the half peak width is close to 37 mV (this value is lower than 57 mV for a reversible one-electron process and higher than 28.5 mV for a single two-electron reversible wave) [29], it can be proposed that the reversible wave is two-electron in nature and it involves proton transfers in equilibrium.…”

Capillary zone electrophoresis in non-aqueous solutions: pH of the background electrolyte

“…A − + H 2 O → A(H 2 O) − ). The pH of the solution consisting of 65 mmol/l benzoic acid and 2.18 mmol/l tetraethylammonium benzoate in ACN (pH = 18.6), on the other hand, is not much affected upon addition of water [83], because the benzoate ion is present as a homoconjugate with the neutral benzoic acid molecule, and thus addition of water has no influence on the pH. It is obvious that the pH of picric acid-picrate buffers in ACN are not much affected by the addition of small amounts of water (or alcohols) because of the weak or negligible tendency of the buffer components for homoand heteroconjugation [84].…”

“…The pH of a buffer prepared, e.g. from 3.6 mmol/l benzoic acid and 30.5 mmol/l tetraethylammonium benzoate in ACN (pH = 23.4) is decreased seriously upon addition of water [83], because the concentration of benzoate (A − ) is reduced by hydrogen bonding with water molecules (i.e. A − + H 2 O → A(H 2 O) − ).…”

Assessment of Two Theoretical Methods to Estimate Potentiometric Titration Curves of Peptides: Comparison with Experiment

“…32) and (2,6-NO 2 PhOH) = 4.9 (ref. 33). Because 2,6-dinitrophenol is a weak acid, given the total concentration of 2,6-dinitrophenol (C HA ) and of its salt (C A −), the pH can be expressed by Eq.…”