Kinetics of the Decomposition of Sulphur Dicyanide in Aqueous Solution

1962 ◽  
Vol 15 (2) ◽  
pp. 211 ◽  
Author(s):  
W Kitching ◽  
RH Smith ◽  
IR Wilson
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Nucleophilic Substitution ◽  
Perchloric Acid ◽  
Reaction Path ◽  
Acid Solutions ◽  
Kinetics Of

The kinetics and stoicheiometry of the decomposition of aqueous solutions of sulphur dicyanide have been studied at temperatures between 0-70 �C and in media ranging from dilute perchloric acid to pH 7. The predominant reaction is nucleophilic substitution at carbon, but in perchloric acid solutions an alternative reaction path has been revealed.

scholarly journals Rates and equilibrium constants for the covalent hydration of 5-bromo-2(1H)-pyrimidinone in aqueous solution

1986 ◽  
Vol 64 (6) ◽  
pp. 1267-1272 ◽  
Author(s):  
Oswald S. Tee ◽  
Jana Pika ◽  
M. Judith Kornblatt ◽  
Michael Trani
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Title Compound ◽  
Equilibrium Constants ◽  
Kinetic Studies ◽  
Kinetics Of

The kinetics of bromination of the title compound (1) have been measured in aqueous solutions of pH 0–6. The change in the order of reaction which occurs around pH 2.5 is explained by 1 reacting via its covalent hydrate, 3. Furthermore, there is sufficient 3 present at equilibrium that the kinetics of its equilibration with 1 were also measured. From these two studies the extent of covalent hydration of 1 is estimated to be 5%.Kinetic studies of the bromination of the dimethyl cation 5 and of its equilibration with the pseudobase 6 were also carried out for the purposes of comparison.The present results for 1, 3, 5, and 6 are compared to earlier results for 2-pyrimidinone and analogous derivatives.

Leaching Kinetics of Colemanite in Perchloric Acid Solutions

2008 ◽  
Vol 41 (5) ◽  
pp. 354-360 ◽  
Author(s):  
Aycan Gür ◽  
M. Emin Alkan
Keyword(s):  
Perchloric Acid ◽  
Acid Solutions ◽  
Leaching Kinetics ◽  
Kinetics Of

KINETICS OF THE OXIDATION OF URANIUM (IV) BY IRON (III) IN AQUEOUS SOLUTIONS OF PERCHLORIC ACID

1955 ◽  
Vol 33 (12) ◽  
pp. 1780-1791 ◽  
Author(s):  
R. H. Betts
Keyword(s):  
Electron Transfer ◽  
Ionic Strength ◽  
Aqueous Solutions ◽  
Perchloric Acid ◽  
Rate Constants ◽  
Kcal Mole ◽  
Kinetics Of Oxidation ◽  
Temperature Coefficients ◽  
Kinetics Of ◽  
Rate Controlling Step

The kinetics of oxidation of uranium (IV) by iron (III) in aqueous solutions of perchloric acid have been investigated at four temperatures between 3.1 °C. and 24.8 °C. The reaction was followed by measurement of the amount of ferrous ion formed. For the conditions (H+) = 0.1–1.0 M, ionic strength = 1.02, (FeIII) = 10−4–10−5 M, and (UIV) = 10−4–10−5 M, the observed rate law is d(Fe2+)/dt = −2d(UIV)/dt[Formula: see text]K1 and K2 are the first hydrolysis constants for Fe3+ and U4+, respectively, and K′ and K″ are pseudo rate constants. At 24.8 °C., K′ = 2.98 sec.−1, and K″ = 10.6 mole liter−1 sec−1. The corresponding temperature coefficients are ΔH′ = 22.5 kcal./mole and ΔH″ = 24.2 kcal./mole. The kinetics of the process are consistent with a mechanism which involves, as a rate-controlling step, electron transfer between hydrolyzed ions.

Tautomeric equilibria and pKa values for 'sulfurous acid' in aqueous solution: a thermodynamic analysis

1979 ◽  
Vol 57 (4) ◽  
pp. 454-457 ◽  
Author(s):  
J. Peter Guthrie
Keyword(s):  
Aqueous Solution ◽  
Free Energy ◽  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Acid Solutions ◽  
Sulfurous Acid ◽  
Free Energy Of Formation ◽  
Dilute Aqueous Solutions ◽  
Sulfite Ion ◽  
Energy Of Formation

The free energy of formation of dimethyl sulfite in aqueous solution can be calculated as −91.45 ± 0.79 kcal/mol; this calculation required measurement of the solubility of dimethyl sulfite. From this value and the pKa of SO(OH)2, using previously reported methods, the free energy of formation of SO(OH)2 can be calculated to be −129.26 ± 0.89 kcal/mol. Comparison of this value with the value obtained from the free energy of formation of 'sulfurous acid' solutions, calculated from the free energy of formation of sulfite ion and the apparent pKa, values, permits evaluation of the free energy of covalent hydration of SO2 as 1.6 + 1.0 kcal/mol, in agreement with earlier qualitative spectroscopic observations. From the apparent pKa and the anticipated pKa values for the tautomers (SO(OH)2, pK1 = 2.3; HSO2(OH), pK1 = −2.6) it is possible to calculate the free energy change for tautomerization of SO(OH)2 to H—SO2(OH) as +4.5 ± 1.2 kcal/mol. All equilibrium constants required for Scheme 1, describing the species present in dilute aqueous solutions of SO2, have been calculated. In agreement with previous Raman studies the major tautomer of 'bisulfite ion' is calculated to be H—SO3−.

ChemInform Abstract: KINETICS OF THE RAPID MONOMER-DIMER EQUILIBRATION OF MOLYBDENUM(VI) IN AQUEOUS PERCHLORIC ACID SOLUTIONS

1975 ◽  
Vol 6 (21) ◽  
pp. no-no
Author(s):  
J. FOLORUNSO OJO ◽  
ROGER S. TAYLOR ◽  
A. GEOFFREY SYKES
Keyword(s):  
Perchloric Acid ◽  
Acid Solutions ◽  
Aqueous Perchloric Acid ◽  
Kinetics Of

The Oxidation of Tetrahydrofuran by Ruthenium Tetroxide

1972 ◽  
Vol 50 (19) ◽  
pp. 3129-3134 ◽  
Author(s):  
Donald G. Lee ◽  
Matthijs Van Den Engh
Keyword(s):  
Perchloric Acid ◽  
Activation Parameters ◽  
Isotopic Labeling ◽  
Acid Solutions ◽  
Ruthenium Tetroxide ◽  
Rate Determining Step ◽  
Rate Of Reaction ◽  
Hydride Abstraction ◽  
Aqueous Perchloric Acid ◽  
Kinetics Of

The kinetics of the oxidation of tetrahydrofuran by ruthenium tetroxide in aqueous perchloric acid solutions have been investigated. The rate of reaction is found to be directly dependent on the concentrations of oxidant and reductant, but inversely dependent on the acidity of the medium. A mechanism involving hydride abstraction in the rate determining step was found to be consistent with the evidence obtained from isotopic labeling and an analysis of the activation parameters (ΔH≠ = 14.0 kcal/mol, ΔS≠ = −18.4 e.u.) of the reaction. This conclusion is further substantiated by noting the similarity between the reactions of ruthenium tetroxide with alcohols and ethers.

Kinetics of the Iodination of Acetophenone in Sulfuric and Perchloric Acid Solutions

1939 ◽  
Vol 61 (10) ◽  
pp. 2791-2798 ◽  
Author(s):  
Lois. Zucker ◽  
Louis P. Hammett
Keyword(s):  
Perchloric Acid ◽  
Acid Solutions ◽  
Kinetics Of
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