Kinetics and mechanism of the oxidation of bisulfite by peroxymonosulfate

Abstract

The oxidation of bisulfite ion by peroxymonosulfate ion, HSOs-, to form sulfate ion has been studied in the pH region 3.8-7.9. The reaction HSOs-+ HS03--* 2S042-+ 2H+ was found to obey the rate law -d[HS05-]/df {fc,aH+ + kbflH*'1 + kc){HSOs-] [HS03 ], where aH+ is the activity of hydrogen ion. At 25 °C and ionic strength 0.0050 M the rate constants fca, kb, and kc have the values 1.27 X 107,6.4X 10-5,and55 M-1 S-1, with the activity of hydrogen ion taken to be dimensionless. For the reaction path corresponding to the ka term, 90% of the reaction yields the intermediate pyrosulfate ion, S2O72-, which then hydrolyzes with about a 1-min lifetime to sulfate and hydrogen ions. Similarly the kc path forms mostly S2O72-as an intermediate. The kb path appears to all go directly to sulfate ion. Possible mechanisms for the various reaction paths are discussed.

Preparation of Purified KHSO5·H2O and nBu4NHSO5 from Oxone by Simple and Efficient Methods

“…Preparation of pure KHSO 5 ·H 2 O and KHSO 5 From a preparative point of view, a comparison of the two reported methods to obtain KHSO 5 ·H 2 O in pure form favors the method described by Connick et al [36] The procedure is easier since the starting material is Oxone, which contains the active oxidant and does not lose activity over time. This method provides the desired pure KHSO 5 ·H 2 O, but requires a laborious removal of water, which is followed by crystallization of the product.…”

“…[34,35] The purification of KHSO 5 ·H 2 O was revisited by Connick et al in the early 90's along with a modified method for its preparation. [36] Essentially, a straightforward filtration protocol starting from Oxone, followed by evaporation and crystallization resulted in the isolation of analytically pure KHSO 5 ·H 2 O. Again, this method received little attention from organic chemists perhaps due to its limitations upon scale-up where the removal of large volumes of water is required.…”

Reaction Mechanism of the Iron(III)‐Catalyzed Autoxidation of Bisulfite in Aqueous Solution: Steady State Description for Benzene as Radical Scavenger

“…Third order rate coefficients that have been reported are in good agreement, with values (adjusted to 297K): Betterton and Hoffmann [24] 1 . 4~ lo7; McElroy and Deister [25] 1.1 x lo7; Connick et al [26] 1 . 0~1 0~; Elias et al [27] 1.0x107dm6mol-2~-1.…”

Kinetics of the uninhibited and ethanol-inhibited CoO, Co2O3 and Ni2O3 catalyzed autoxidation of sulfur(IV) in alkaline medium

“…The pH of zero point charge, pH zpc (= (pK 1 s + pK 2 s ), has a value of 11.4 for Co(OH) 2 [27], which suggests that in the range of pH used in this study, the dominant form of CoO is -Co(OH)(H 2 O + ). In the same pH range, sulfur(IV) would be largely present as SO 3 2-(pK a of HSO 3 -= 6.13) [18].…”