The Dissociation Constants and Conductivities of Mono-, Di- and Triethylamine in Aqueous Solution

1973 ◽  
Vol 51 (4) ◽  
pp. 551-555 ◽  
Author(s):  
Alan Newton Campbell ◽  
Sing-Yeung Lam

The conductances of the mono-, di-, and triethylamines, and their hydrochlorides, in aqueous solution, have been determined. Corrections for the formation of amine carbonates and hydrolysis of the halides were made. By using the Kohlrausch law and the method of Shedlovsky and Kay, basic dissociation constants for the amines have been computed. The basic strength of this series has been found to conform to the usual trend for other series of aliphatic amines.

The kinetics of the bromination of diethyl malonate have been investigated in aqueous solution at 25°. Under suitable conditions the rate of bromination is independent of the bromine concentration, and is determined by the rate at which the ester loses a proton to basic ions or molecules in the solution. Measurements in buffer solutions were used to obtain values for the catalytic constants of ten basic species. There is no detectable catalysis by acids, a slight increase in velocity in strongly acid solutions being traceable to hydrolysis of the ester group. The catalytic constants of six basic anions are related to the dissociation constants of the corresponding acids by an expression of the type due to Bronsted. The ions OH - , H 2 BO - 2 and OBr - do not conform to this relation, and reasons for these discrepancies are discussed. In its general kinetic behaviour the bromination of diethyl malonate conforms to the regularities previously shewn to exist in the ionization of substituted ketones (Bell 1943).


Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.


1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.


1971 ◽  
Vol 26 (6) ◽  
pp. 543-545
Author(s):  
Leopoldo J. Anghileri ◽  
Esther S. Miller

The hydrolysis of 32P-sodium polyphosphates (linear and cross-linked) in aqueous solution has been studied. The radiometric determinations indicate that the ortho-phosphate formation is a slow reaction, and that the amount formed by the linear variety is higher than that produced by the cross-linked form. There is a significant formation of metaphosphates during the hydrolysis of the cross-linked polyphosphate which is missing or at least reduced to a much lesser extent in the case of the linear polyphosphate.


1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.


Author(s):  
A. V. Podol'skii ◽  
L. S. German ◽  
I. L. Knunyants

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.


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