Volumes of Activation for the Base Hydrolysis of [Rh(NH3)5X]2+ Complex Ions

1979 ◽  
Vol 32 (12) ◽  
pp. 2589 ◽  
Author(s):  
DA Palmer
Keyword(s):  
Partial Molar Volumes ◽  
Base Hydrolysis ◽  
Volume Data ◽  
Complex Ions ◽  
Molar Volumes ◽  
Base Mechanism ◽  
Hydrolysis Of ◽  
Conjugate Base

The pressure dependencies of the rates of base hydrolysis of [Rh(NH3)5X]2+ were measured at 313.2 K and μ1M, where X = Cl-, Br-, I- and NO3-, in the range 1-1500 bar. The respective Δν‡exp values are 19.3 � 0.9, 20.2 � 0.5, 20.4 � 0.5 and 22.3 � 0.9cm3 mol-1. The partial molar volumes of these complexes, as well as those of other relevant pentaamminerhodium(III) complexes, were also determined. The volume data are discussed in terms of the conventional dissociative conjugate base mechanism. The Δν‡exp for the aquation of [Rh(NH3)5NO3]2+ was found to be -6.9 � 0.4cm3 mol-1 at 313.2K, [H+] 0.005M and μ0.1 M. An I mechanism is favoured for this process.

Octahedral cobalt(III) complexes of the chloropentammine type. XVIII. Hydrolysis of some Chloroanilinebis(ethylenediamine)cobalt(III) complexes, and a rationalization for the conjugate-base and ion-pair mechanisms

1969 ◽  
Vol 22 (9) ◽  
pp. 1851 ◽  
Author(s):  
SC Chan ◽  
OW Lau
Keyword(s):  
Chloride Ion ◽  
Ion Pair ◽  
Base Hydrolysis ◽  
Methyl Substituent ◽  
Substituted Anilines ◽  
First Order ◽  
Base Mechanism ◽  
Higher Temperature ◽  
Hydrolysis Of ◽  
Conjugate Base

The kinetics for the appearance of chloride ion from aqueous solutions of the cis-chloroanilinebis(ethylenediamine)cobalt(III) cation are determined over the pH ranges of 2-3 at 40.0� and of 8-9 at 0�. By using self-buffered mixtures, the rate constants for the reaction are also measured at 40.0� as a function of the concentration of complex or of free aniline. The results are discussed in terms of the conjugate- base mechanism. A rationalization of this mechanism and the ion-pair mechanism is proposed to incorporate the base hydrolysis of other previously investigated systems where the complexes are decidedly much less acidic. At a higher temperature (65.0�), both chloride ion and aniline are liberated at similar rates, and the process is treated as parallel first-order reactions. By using complexes with meta- and para-substituted anilines, the effect of the methyl substituent on reactivity is studied.

Partial molar volumes of aqueous 1:1 and 2:1 electrolytes and a structure model

1976 ◽  
Vol 54 (5) ◽  
pp. 824-832 ◽  
Author(s):  
Lowell W. Bahe ◽  
Kathryn A. Jung
Keyword(s):  
Free Energy ◽  
Energy Equation ◽  
Partial Molar Volumes ◽  
Quantitative Agreement ◽  
Structure Model ◽  
Volume Data ◽  
Molar Volumes ◽  
A Value ◽  
Direct Measurements ◽  
Gradient Forces

An expression for partial molar volumes is derived from the free energy equation based on field-dielectric-gradient forces, as well as coulombic forces, between ions in structured solution. Qualitative agreement between the model and experimental partial molar volume data is very good. Excellent quantitative agreement is obtained by adopting for a universal parameter of the theory a value that implies [Formula: see text] for water at 25 °C and 1 atm. The latter value is compatible with data obtained from direct measurements.

Base hydrolysis of trans-Halogenoamminebis(dimethylglyoximato) (III). Complexes

1969 ◽  
Vol 22 (12) ◽  
pp. 2569 ◽  
Author(s):  
SC Chan ◽  
PY Leung
Keyword(s):  
Equilibrium Constants ◽  
Base Hydrolysis ◽  
Hydroxide Ion ◽  
First Order ◽  
Rate Determining Step ◽  
Rapid Formation ◽  
Pseudo First Order ◽  
Conjugate Bases ◽  
Hydrolysis Of ◽  
Conjugate Base

The disappearance of trans-[Co(LH)2(NH3)X] (LH = dimethylglyoximate ion, X = chloride or bromide) has been studied in aqueous solutions over a range of alkali concentrations at various temperatures. The kinetics were done with excess of hydroxide ion at a constant ionic strength so that pseudo first-order rate constants were obtained in all the runs. The results were interpreted in terms of the rapid formation of a pre- equilibrium species which then reacts in a rate-determining step to give products. The relatively large equilibrium constants support a conjugate-base pre-equilibrium, in which the proton is lost from oxygen, while the relatively low reactivities of the conjugate-bases are consistent with the absence of electropositive electromeric effects. The similarity in the reactivities of the chloro and the bromo conjugate-bases suggests the possibility of an SN2CB mechanism.

scholarly journals Volumetric studies of alcohols in water and aqueous micelle solutions of cetyltrimethylammonium bromide

1970 ◽  
Vol 24 (2) ◽  
pp. 143-157 ◽  
Author(s):  
T Parvin ◽  
M Alauddin ◽  
M Rokonuzzaman
Keyword(s):  
Molar Volume ◽  
Apparent Molar Volume ◽  
Cetyltrimethylammonium Bromide ◽  
Surfactant Concentration ◽  
Partial Molar Volumes ◽  
Chemical Society ◽  
Volume Data ◽  
Palisade Layer ◽  
Molar Volumes ◽  
Partial Molar Expansibilities

The volumetric properties of 1-propanol, cyclohexanol and butoxyethanol in water and CTAB water mixtures have been studied. The apparent molar volumes of 1-propanol, cyclohexanol and butoxyethanol in water and in aqueous solutions of CTAB were determined from density data. The partial molar volumes of the alcohols in water and aqueous micelle solutions at infinite dilution, V20(mic) were obtained from apparent molar volume data and compared with the corresponding values. The standard partial molar expansibilities, E20(mic) of the solubilizates were evaluated from V20(mic) data at various temperatures. The volumetric studies of alcohols in CTAB micelles indicate that alcohols on the average are preferentially solubilized in the palisade layer of the micelle and increasing amount of each is transferred more deep into the palisade layer of the micelle with increasing surfactant concentration and temperature. The results of standard partial molar volume, V20 and standard partial molar expansibilities, E20 are reported and discussed. DOI: http://dx.doi.org/10.3329/jbcs.v24i2.9703 Journal of Bangladesh Chemical Society, Vol. 24(2), 143-157, 2011

Molten salt mixtures. XI. Integral and partial molar volumes in the molten salt systems PbCl2 + NaCl, PbCl2 + RbCl, PbCl2 + CsCl, CdCl2 + RbCl, and CdCl2 + CsCl

1966 ◽  
Vol 19 (9) ◽  
pp. 1591 ◽  
Author(s):  
H Bloom ◽  
PWD Boyd ◽  
JL Laver ◽  
J Wong
Keyword(s):  
Molten Salt ◽  
Molar Volume ◽  
Partial Molar Volume ◽  
Binary Systems ◽  
Partial Molar Volumes ◽  
Complex Ions ◽  
Molar Volumes ◽  
Temperature Range ◽  
Salt Mixtures ◽  
Salt Systems

The densities of molten PbCl2, CsCl, and RbCl and of the molten salt systems PbCl2 + NaCl, PbCl2 + RbCl, PbCl2 + CsCl, CdCl2 + RbCl, and CdCl, + CsCl have been measured to an accuracy of �0.1% by an Archimedean method over a considerable temperature range. Integral and partial molar volume isotherms have been constructed for the above binary systems and are interpreted to show that complex ions are formed in all but the PbCl2+NaCl system.

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