Kinetics and mechanism of the reduction of dichromate ion by 2-methyl pentane-2,4-diol in aqueous hydrochloric acidic medium

Abstract

Oxidative properties of Cr(VI) are of considerable importance in both analysis and oxidation of organic and inorganic substrates 1,2,3. Cr (VI) in water exists as CrO 4 2-, HCr 2 O 7 2and H 2 Cr 2 O 7 2,4. Of all these species, HCrO 4 has been identified as the only active oxidizing species in aqueous acidic solution 1,2,5,6,7. Although some kinetic information has been published on the oxidation of secondary alcohol by Cr(VI) 1,2, 8-16 complementary studies on its possible reaction pathways are scanty. It is in the light of this that the present work was undertaken with the aim of providing relevant information on the plausible mechanism for the electron transfer reaction of 2-methylpentane-2,4-diol. EXPERIMENTAL Materials 2-methylpentane-2,4-diol (BDH) hereafter referred to as diol was used as supplied in making its standard solution. Sodium dichromate solution in distilled water was then standardized using titrimetric method 17. A stock solution of HCl was prepared by diluting the commercial acid (M&B) and the solution was standardized titrimetrically using sodium carbonate. Stock solutions of sodium methanoate, sodium chloride and sodium ethanoate were prepared from Analar grade salts.

Preliminary Study on the Kinetics and Mechanism of the Oxidation of Naphthol Green B by Dichromate Ion in Aqueous Hydrochloric Acid Medium

“…prepared by dissolving known quantities in distilled water. 1.0 mol dm -3 solution of hydrochloric acid (BDH) was prepared (36%, specific gravity 1.18) and standardized titrimetrically (Idris et al, 2005). The reaction stoichiometry was determined spectrophotometrically using the mole ratio method (Mohammed et al, 2009).…”

Electron Transfer Reactions of Bridged Binuclear Iron(iii)- Complexes: a Review

“…The rate law of these reactions is presented in equation (39) (46) By applying steady state approximation and further resolving equation ( 46) brings rate to Reduction of adipato-bridged binuclear Fe(III)salen complex by another oxo-sulphur compounds, dithionite ion [5], trioxosulfate(IV) ion [6] and dithionate ion [57]was investigated in perchloric acidic medium. Stoichiometry of the reactions was monitored spectrophotometrically at 455 nm.…”