title: Protonation and solvent extraction of N-p-tolylbenzohydroxamic acid in hydrochloric acid medium.
abstract: the protonation of N-p-tolylbenzohydroxamic acid (p-TBHA) in aqueous hydrochloric acid has been investigated by determination of its distribution between cyclohexane and hydrochloric acid. The pK(a) value found was - 2.30 +/- 0.02 at 30 degrees . The solubility of p-TBHA as a function of hydrochloric acid concentration has also been determined. At lower acid concentrations the solubility decreases owing to a salting-out effect, whereas at higher concentrations it increases because of formation of the more hydrophilic protonated species and a salting-in effect. Intramolecular hydrogen-bonding observed in p-TBHA provides evidence for protonation of the nitrogen atom.
authors.affiliation: Department of Chemistry, Ravishankar University, Raipur 492010, India.
authors.forename: R
authors.initials: R
authors.lastname: Pande
authors.forename: S G
authors.initials: SG
authors.lastname: Tandon