scholarly journals THE KINETICS OF SAPONIFICATION OF IODOACETIC ACID BY SODIUM HYDROXIDE AND BY CERTAIN ALKALINE BUFFER SOLUTIONS

1936 ◽  
Vol 19 (6) ◽  
pp. 899-906 ◽  
Author(s):  
R. Brdička
Keyword(s):  
Ionic Strength ◽  
Boric Acid ◽  
Sodium Hydroxide ◽  
Salt Effect ◽  
Iodoacetic Acid ◽  
Borate Buffer ◽  
Polarographic Method ◽  
Buffer Solutions ◽  
Glycollic Acid ◽  
Kinetics Of

1. The rate of the saponification of iodoacetic acid in sodium hydroxide and alkaline buffer solutions yielding glycollic acid was measured by means of Heyrovský's polarographic method. 2. From the bimolecular velocity constants, increasing with the ionic strength of the solution, the Brönsted factor, F, which characterizes the primary salt effect, was calculated. 3. In the borate buffer solutions the monomolecular constants of the saponification were determined which, at values above the pH of neutralization of boric acid, show a proportionality to the concentration of hydroxyl anions. Below the pH of neutralization of boric acid, they are proportional to the concentration of borate anions.

Kinetics of oxidation of cis-bis(ethylenediamine)isothiocyanatonitrocobalt(III) ion with peroxodisulphate

1979 ◽  
Vol 44 (12) ◽  
pp. 3588-3594 ◽  
Author(s):  
Vladislav Holba ◽  
Olga Volárová
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Oxidation Kinetics ◽  
Reaction Rate ◽  
Salt Effect ◽  
Activation Parameters ◽  
Reaction Products ◽  
Kinetics Of Oxidation ◽  
Thermodynamic Activation Parameters ◽  
Kinetics Of

The oxidation kinetics of cis-bis(ethylenediamine)isothiocyanonitrocobalt(III) ion with peroxodisulphate was investigated in the medium of 0.01 M-HClO4 in dependence on the ionic strength and temperature and the reaction products were identified. Extrapolated values of thermodynamic activation parameters were determined from the temperature dependence of the rate constants extrapolated to zero ionic strength. The distance of the closest approach was estimated for the reacting ions by evaluating the primary salt effect. To elucidate the mechanism, the influence of the cyclic polyether 18-crown-6 on the reaction rate was followed.

scholarly journals THE KINETICS OF THE REACTION WHICH TAKES PLACE BETWEEN IODOACETIC ACID AND GLYCINE

1936 ◽  
Vol 19 (5) ◽  
pp. 843-866 ◽  
Author(s):  
R. Brdička
Keyword(s):  
Kinetic Equations ◽  
Iodoacetic Acid ◽  
Anionic Form ◽  
Amino Group ◽  
Polarographic Method ◽  
Salt Effects ◽  
Reaction Proceeds ◽  
Kinetics Of

1. The kinetics of the reaction which takes place between glycine and iodoacetic acid was studied by means of the polarographic method. 2. On the basis of kinetic equations, evidence was obtained that (a) The reaction proceeds in two steps in which the hydrogens of the amino group are consecutively replaced by the acetyl radicals, the velocity constants being in the ratio 2:1. (b) Only the anionic form of glycine is able to react since the velocity constants at any pH are proportional to the concentration of glycine anion. (c) The reaction is of the ionic type, showing a positive salt catalysis, which, according to Brönsted's hypothesis, involves the primary and the secondary salt effects. 3. The fact that only the glycine anion is able to react was explained as being due to the existence of an unbonded pair of electrons on the nitrogen in the NH2 group. The NH3+ group, however, in which these electrons are shared by H+, must, therefore, be inactive.

Oxidation kinetics of trans-aqua-bis(ethylenediamine)-isothiocyanatocobalt(III) ion with peroxodisulphate

1979 ◽  
Vol 44 (4) ◽  
pp. 1052-1059 ◽  
Author(s):  
Olga Volárová ◽  
Vladislav Holba
Keyword(s):  
Ionic Strength ◽  
Temperature Dependence ◽  
Rate Constants ◽  
Oxidation Kinetics ◽  
Salt Effect ◽  
Activation Parameters ◽  
Thermodynamic Activation Parameters ◽  
Ionic Reactions ◽  
Kinetics Of

Oxidation kinetics of trans-aqua-bis(ethylenediamine)cobalt(III) ion with peroxodisulphate have been investigated in 0.01M-HClO4 medium within the ionic strength and temperature intervals 0.0411 to 0.4415M and 315.5 to 336.9 K, respectively. From the temperature dependence of the rate constants extrapolated to zero ionic strength the extrapolated values of thermodynamic activation parameters have been calculated. The data obtained by investigation of the primary salt effect have been confronted with relations valid for ionic reactions.

Study of the Cu(II) removal from aqueous solutions by adsorption on titania

2013 ◽  
Vol 12 (3) ◽  
pp. 239-247
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Toxic Metals ◽  
Low Cost ◽  
Lateral Interaction ◽  
Tio2 Surface ◽  
High Toxicity ◽  
Removal Of Heavy Metals ◽  
Solution Parameters ◽  
Kinetics Of

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.

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