The Electrolyte Effect upon the Kinetics of the Bromoacetate–Thiosulfate Reaction in n-Propyl Alcohol–Water Solutions.

Ciapetta, F. G.; Tomlinson, H. M.

doi:10.1021/j150486a010

Cited by 6 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After bringing the two separate solutions to thermal equilibrium, they were mixed and the reaction rate was followed by taking samples at specified intervals of time. The latter procedure involved tripping the stop watch at the in- Tables III-VII represent results of the present investigation and those taken in part from the work of Ciapetta and Tomilinson (10). Data summarized in the remaining tables are those used for the plots in Fig.…”

Section: Methodsmentioning

confidence: 96%

See 1 more Smart Citation

Kinetics of the Thiosulfate-Bromoacetate Reaction in the Presence of Electrolytes

Corsaro¹,

Stephens²

1958

J. Electrochem. Soc.

View full text Add to dashboard Cite

The reaction between thiosulfate and bromoacetate ions in solvent mixtures of different dielectric constant and in the presence of added salts fails to give results conforming to the predictions of the BrSnsted primary salt effect. The deviation from theory is particularly high in solvents of low dielectric constant and in the presence of higher valence type electrolytes. A mechanism for the over-all reaction is proposed to account for the apparent abnormalities. New experimental data are added to those previously obtained and are correlated with the BrSnsted-Christiansen-Scatchard theoretical expressions which relate the log of the molar reaction rate constants to the dielectric constant of the solvent mixture in which reaction takes place, the ionic strength of the solutions making up the reaction mixture, and the size and charge of the intermediate complex assumed to be formed in ionic reactions. The essential condition in the postulated mechanism is that the reaction proceeds through the formation of a complex or ion pair between the added cation and thiosulfate ion, followed by reaction of this complex with bromoacetate ion.The reaction between bromoacetate and thiosulfate ions in several solvent systems has been investigated extensively (3-10). The conclusions reached by Ciapetta and Tomilinson (10) are pertinent to the remarks to be made in the present discussion. They may be summarized as follows.(A) Specific solvent effects are minor. Observed rate constant data obtained with different isodielectric constant solvents, but with identical concentrations of reactants and added salt, are of the same order of magnitude.(B) Strontium and calcium nitrate mixed with reactants produce high rate constants. Rate constants level off to almost constant values when these salts are present in excess of the reactants.(C) When lanthanum nitrate is the added salt, reaction rate constants are as high as one hundredfold times those anticipated from the BrSnstedChristiansen-Scatchard theoretical expressions (1,2). When the reaction is allowed to take place in solvents of low dielectric constant, the rate constants increase in value with increase in the added salt concentration, reaching a maximum when the added salt concentration equals that of reactants, then fall off with further increases in added salt.(D) LaMer and Davis (3) have shown that when solvents range in dielectric constant from 20 to 35 so that constant DT values are obtained, the observed energies of activation for the reactions with added salt are the same as those in which salt addition is absent. They concluded that abnormal rate constants were the result of certain electrostatic attractions leading to possible ion pair formations. Ciapetta and Tomilinson postulated an ion pair (LaS~O~BrAc) ~ since they observed that the maximum in the rate constant value was usually obtained when the salt concentration added with reactants was equal to that of the reactants. They concluded further that rate constants were lower in the presence of greater concentrations of ...

show abstract

Section: Methodsmentioning

confidence: 96%

“…The reaction between bromoacetate and thiosulfate ions in several solvent systems has been investigated extensively (3)(4)(5)(6)(7)(8)(9)(10). The conclusions reached by Ciapetta and Tomilinson (10) are pertinent to the remarks to be made in the present discussion.…”

mentioning

confidence: 84%

Kinetics of the Thiosulfate-Bromoacetate Reaction in the Presence of Electrolytes

Corsaro¹,

Stephens²

1958

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Ciapetta & Tomlinson (136), investigating the reaction between bromo acetate and thiosulfate in aqueous propyl alcohol, have shown that the rate exhibits a strong maximum at a concentration of added La+3 corresponding to the stoichiometric formation of LaS20a+, and have inferred that this species is one of the actual reactants. The correctness of this hypothesis is confirmed by the observation (137) that the reaction in water as well as in the aqueous alcohol can be described by a reaction scheme which includes LaS20a+ as a reactant with bromoacetate; and, moreover, that this contri bution to the rate shows a salt effect as expected from the Br¢nsted-Debye Hiickel theory.…”

Section: Medium Effectsmentioning

confidence: 99%

Reaction Kinetics

Powell¹

1952

Annu. Rev. Phys. Chem.

View full text Add to dashboard Cite

Since scientific papers which could be catalogued as reaction kinetics are currently being published at a rate of more than a thousand per year, a simple bibliography of one year's pUblications would fill the space allotted this review. Fortunately for the reviewer, many papers fall into special fields such as photochemistry, polymerization, contact catalysis, isotopic studies, or biochemical kinetics, which will be reviewed separately in the present volume or succeeding volumes of the Annual Review of Physical Chemistry.

show abstract

“…The rate of the bromoacetatethiosulfate reaction was measured in aqueous solutions of methanol, propanol, butanol, glycerol, urea, and sucrose(Ciapetta and Tomlinson, 1951;Davis and LaMer, 1942;LaMer and Kamner, 1935a; …”

mentioning

confidence: 99%