Dissolution Kinetics of Pure Zinc: The Effect of Bulk Solution Concentration and Temperature Studied by the Lead-In Pencil Electrode Technique

2017 ◽  
Vol 164 (13) ◽  
pp. C758-C767 ◽  
Author(s):  
Davood Nakhaie ◽  
Edouard Asselin
Keyword(s):  
Dissolution Kinetics ◽  
Solution Concentration ◽  
Bulk Solution ◽  
Pure Zinc ◽  
Kinetics Of ◽  
Electrode Technique

The dissolution of calcite at pH > 7: kinetics and mechanism

1990 ◽  
Vol 330 (1609) ◽  
pp. 47-70 ◽  
Keyword(s):  
Calcium Carbonate ◽  
Solubility Product ◽  
Dissolution Kinetics ◽  
Theoretical Modelling ◽  
Normal Rate ◽  
Bulk Solution ◽  
Rate Law ◽  
Rate Laws ◽  
Ph Conditions ◽  
Kinetics Of

A technique is described that allows an assessment of the various candidate rate laws that have been proposed to predict the dissolution kinetics of calcite under high pH conditions. A combination of theoretical modelling and experimentation allows us to choose the following rate law as that which best fits the observed data: rate ( mol c m − 2 s − 1 ) = k − k ′ [ C a 2 + ] s [ CO 3 2 − ] s ′ , where k ′ = k / K sp and K sp is the solubility product of calcium carbonate. The modelling developed differs from previous studies in that it deals in terms of surface concentrations of reactants, [ Ca 2 + ] s and [ CO 3 2 − ] , as opposed to those present in bulk solution.

scholarly journals Efficacy of a Phosphate-Charged Soil Material in Supplying Phosphate for Plant Growth in Soilless Root Media

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Young-Mi Oh ◽  
Paul V. Nelson ◽  
Dean L. Hesterberg ◽  
Carl E. Niedziela
Keyword(s):  
Plant Growth ◽  
Solution Concentration ◽  
Bulk Solution ◽  
P Deficiency ◽  
Soil Material ◽  
Hydrous Oxides ◽  
Acceptable Range ◽  
Root Media ◽  
Phosphate Fertilization ◽  
Phosphate Leaching

A soil material high in crystalline Fe hydrous oxides and noncrystalline Al hydrous oxides collected from the Bw horizon of a Hemcross soil containing allophane from the state of Oregon was charged with phosphate-P at rates of 0, 2.2, and 6.5 mg·g−1, added to a soilless root medium at 5% and 10% by volume, and evaluated for its potential to supply phosphate at a low, stable concentration during 14 weeks of tomato (Solanum esculentumL.) seedling growth. Incorporation of the soil material improved pH stability, whether it was charged with phosphate or not. Bulk solution phosphate-P concentrations in the range of 0.13 to 0.34 mg·dm−3were associated with P deficiency. The only treatment that sustained an adequate bulk solution concentration of phosphate-P above 0.34 mg·dm−3for the 14 weeks of testing contained 10% soil material charged with 6.5 mg·g−1P, but initial dissolved P concentrations were too high (>5 mg·g−1phosphate-P) from the standpoint of phosphate leaching. The treatment amended with 10% soil material charged with 2.2 mg·g−1P maintained phosphate-P within an acceptable range of 0.4 to 2.3 mg·dm−3for 48 d in a medium receiving no postplant phosphate fertilization.

scholarly journals Single entity electrochemistry and the electron transfer kinetics of hydrazine oxidation

Nano Research ◽  
2021 ◽  
Author(s):  
Ruiyang Miao ◽  
Lidong Shao ◽  
Richard G. Compton
Keyword(s):  
Electron Transfer ◽  
Bulk Solution ◽  
Relative Contribution ◽  
Rate Determining Step ◽  
Multistep Process ◽  
Ph Range ◽  
Electro Catalytic Oxidation ◽  
Single Particle Impact ◽  
The Impact ◽  
Kinetics Of

AbstractThe mechanism and kinetics of the electro-catalytic oxidation of hydrazine by graphene oxide platelets randomly decorated with palladium nanoparticles are deduced using single particle impact electrochemical measurements in buffered aqueous solutions across the pH range 2–11. Both hydrazine, N2H4, and protonated hydrazine N2H5+ are shown to be electroactive following Butler-Volmer kinetics, of which the relative contribution is strongly pH-dependent. The negligible interconversion between N2H4 and N2H5+ due to the sufficiently short timescale of the impact voltammetry, allows the analysis of the two electron transfer rates from impact signals thus reflecting the composition of the bulk solution at the pH in question. In this way the rate determining step in the oxidation of each specie is deduced to be a one electron step in which no protons are released and so likely corresponds to the initial formation of a very short-lived radical cation either in solution or adsorbed on the platelet. Overall the work establishes a generic method for the elucidation of the rate determining electron transfer in a multistep process free from any complexity imposed by preceding or following chemical reactions which occur on the timescale of conventional voltammetry.

Short time dissolution kinetics of refractory elements Fe, Al, and Ti in Asian outflow-impacted marine aerosols and implications

2013 ◽  
Vol 79 ◽  
pp. 93-100 ◽  
Author(s):  
Shih-Chieh Hsu ◽  
Fei-Jan Lin ◽  
Tsun-Hsien Liu ◽  
Shuen-Hsin Lin ◽  
Shuh-Ji Kao ◽  
...  
Keyword(s):  
Dissolution Kinetics ◽  
Marine Aerosols ◽  
Refractory Elements ◽  
Short Time ◽  
Kinetics Of
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