Catalytic activity of transition metals in hydrogenolysis of ethane calculated by the simplex method

1981 ◽  
Vol 46 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Karel Kuchynka ◽  
Jiří Fusek ◽  
Oldřich Štrouf
Keyword(s):  
Heat Capacity ◽  
Catalytic Activity ◽  
Transition Metals ◽  
Simplex Method ◽  
Molar Heat Capacity ◽  
Atomic Radius ◽  
Chemical Significance ◽  
Physico Chemical ◽  
Physical Importance ◽  
First Ionization Potential

The catalytic activity of transition metals in hydrogenolysis of ethane was approximated by a polynomial of second order with variables of basic physical importance, viz., molar heat capacity, covalent atomic radius of the metal, heat of melting, and first ionization potential of the metal atom. The physico-chemical significance of the correlation of these variables with the catalytic activity of transition metals is discussed.

Modelling of the catalytic Fischer-Tropsch synthesis by pattern recognition. Chemisorption and dissociation of carbon monoxide on metals

1981 ◽  
Vol 46 (10) ◽  
pp. 2336-2344 ◽  
Author(s):  
Oldřich Štrouf ◽  
Karel Kuchynka ◽  
Jiří Fusek
Keyword(s):  
Pattern Recognition ◽  
Carbon Monoxide ◽  
Transition Metals ◽  
Dimensionality Reduction ◽  
Fischer Tropsch ◽  
Chemical Significance ◽  
Physico Chemical ◽  
Dependent Variables ◽  
Physical Importance ◽  
Weakly Dependent

A set of forty nine metals was classified with respect to chemisorption of carbon monoxide and a set of nineteen transition metals was similarly treated with respect to dissociation of the chemisorbed molecule. In both cases the metals were characterized by a set of fifteen variables of basic physical importance. Dimensionality reduction yielded eight linearly weakly dependent variables related to chemisorption of CO whereas the reduced set for dissociation had four parameters only. The physico-chemical significance of the characterizing linearly weakly dependent variables is discussed.

Approximation of adsorption heats of carbon monoxide on transition metals by means of an empirical model

1983 ◽  
Vol 48 (10) ◽  
pp. 2735-2739
Author(s):  
Jiří Fusek ◽  
Oldřich Štrouf ◽  
Karel Kuchynka
Keyword(s):  
Carbon Monoxide ◽  
Heat Capacity ◽  
Transition Metals ◽  
Molar Heat Capacity ◽  
Metal Adsorption ◽  
Heat Of Fusion ◽  
Class Structure ◽  
Fundamental Parameters ◽  
Adsorption Heats ◽  
Pauling Electronegativity

The class structure of transition metals chemisorbing carbon monoxide was determined by expressing the following fundamental parameters in the form of functions: The molar heat capacity, the 1st and 2nd ionization energy, the heat of fusion, Pauling electronegativity, the electric conductivity, Debye temperature, the atomic volume of metal. Adsorption heats have been predicted for twelve transition metals.

Heat capacities and enthalpies of fusion and transformation for solvates of some salts with dimethyl sulfoxide and dimethylformamide

1988 ◽  
Vol 53 (12) ◽  
pp. 3072-3079
Author(s):  
Mojmír Skokánek ◽  
Ivo Sláma
Keyword(s):  
Heat Capacity ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Dimethyl Sulfoxide ◽  
Liquidus Temperature ◽  
Molar Heat Capacity ◽  
Solid Phase ◽  
Zinc Nitrate ◽  
Heat Capacities ◽  
Liquid Phases

Molar heat capacities and molar enthalpies of fusion of the solvates Zn(NO3)2 . 2·24 DMSO, Zn(NO3)2 . 8·11 DMSO, Zn(NO3)2 . 6 DMSO, NaNO3 . 2·85 DMSO, and AgNO3 . DMF, where DMSO is dimethyl sulfoxide and DMF is dimethylformamide, have been determined over the temperature range 240 to 400 K. Endothermic peaks found for the zinc nitrate solvates below the liquidus temperature have been ascribed to solid phase transformations. The molar enthalpies of the solid phase transformations are close to 5 kJ mol-1 for all zinc nitrate solvates investigated. The dependence of the molar heat capacity on the temperature outside the phase transformation region can be described by a linear equation for both the solid and liquid phases.

Complexation of amoxicillin by transition metals: Physico-chemical and antibacterial activity evaluation

2021 ◽  
Vol 142 ◽  
pp. 107936
Author(s):  
A. Hrioua ◽  
A. Loudiki ◽  
A. Farahi ◽  
F. Laghrib ◽  
M. Bakasse ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Transition Metals ◽  
Activity Evaluation ◽  
Physico Chemical

Capacité calorifique de polyélectrolytes en solution

1985 ◽  
Vol 63 (7) ◽  
pp. 1568-1571 ◽  
Author(s):  
Hubert Daoust ◽  
Hoa Le Thanh ◽  
Pierre Ferland ◽  
Daniel St-Cyr
Keyword(s):  
Heat Capacity ◽  
Sodium Salt ◽  
Polyacrylic Acid ◽  
Molar Heat Capacity ◽  
Conformational Transformation ◽  
Polymethacrylic Acid ◽  
High Dilution ◽  
Constant Concentration ◽  
Apparent Molar Heat Capacity ◽  
Low Concentrations

Heat capacities of polyelectrolytes in aqueous solutions have been measured at 25 °C using a Picker-type dynamic micro-calorimeter. The precision of the apparatus is such that it is possible to calculate the apparent molar heat capacity [Formula: see text] of the solute, even at high dilution. The polymers that were studied include polymethacrylic acid (PMAH) and polyacrylic acid (PAH), as well as its sodium salt and the sodium salt of the polystyrènesulfonate. For the salts, the results show that the value of [Formula: see text] decreases rapidly with dilution to low concentrations; this result is in perfect concordance with a relation derived from the theory of Lifson and Katchalsky. A study of the variation of [Formula: see text] at a constant concentration, with the extent of the neutralization of the acids PMAH and PAH has also been conducted. As has been shown previously, the chain of the PMAH undergoes a conformational transformation when the level of neutralization gets close to 25%. This transformation implies an increase of the value of [Formula: see text] [Journal translation]

scholarly journals Generality of Correlation between Yield and Reduced Mass of Raw Materials in Organic Reactions

2021 ◽  
Author(s):  
Masatoshi Kawashima
Keyword(s):  
Molecular Weight ◽  
Heat Capacity ◽  
Molar Heat Capacity ◽  
Raw Materials ◽  
Order Approximation ◽  
Product Yield ◽  
Rotatable Bond ◽  
Carbon Chains ◽  
Synthetic Reactions ◽  
Aliphatic Carbon

To validate a generality of the correlation between product yield and reduced mass of raw materials, the regression analysis of 129 reaction examples (55 as a sample size) including at least 66 types of reactions used in syntheses of natural products such as peptides and terpenes was conducted. It was possible to predict a yield of a variety of synthetic reactions for a synthesis of natural product with many aliphatic carbon chains by applying a reduced mass, adjusted with a molecular weight and the number of rotatable bond, to the regression equation. Moreover, it was found that the increase in yield due to a use of the adjusted reduced mass correlated with the harmonic mean of the molar heat capacity of raw materials and was expressed as a second-order approximation within the analysis range.<br>

scholarly journals Generality of Correlation between Yield and Reduced Mass of Raw Materials in Organic Reactions

2021 ◽  
Author(s):  
Masatoshi Kawashima
Keyword(s):  
Molecular Weight ◽  
Heat Capacity ◽  
Molar Heat Capacity ◽  
Raw Materials ◽  
Order Approximation ◽  
Product Yield ◽  
Rotatable Bond ◽  
Carbon Chains ◽  
Synthetic Reactions ◽  
Aliphatic Carbon

To validate a generality of the correlation between product yield and reduced mass of raw materials, the regression analysis of 129 reaction examples (55 as a sample size) including at least 66 types of reactions used in syntheses of natural products such as peptides and terpenes was conducted. It was possible to predict a yield of a variety of synthetic reactions for a synthesis of natural product with many aliphatic carbon chains by applying a reduced mass, adjusted with a molecular weight and the number of rotatable bond, to the regression equation. Moreover, it was found that the increase in yield due to a use of the adjusted reduced mass correlated with the harmonic mean of the molar heat capacity of raw materials and was expressed as a second-order approximation within the analysis range.<br>

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