entropy of activation

[′en·trə·pē əv‚ak·tə′vā·shən]

(physical chemistry)

The difference in entropy between the activated complex in a chemical reaction and the reactants.

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The values of change in enthalpy of activation (IH*), change in free energy of activation (IG*) and change in entropy of activation (IS*) were calculated using following relations and tabulated in Table 4.

Photometric Study of Oxidation of Ascorbic Acid by Methylene Green in Aqueous Alcoholic System

[DELTA]S[double dagger] is the entropy of activation (J[mol.sup.-1][K.sup.-1]).

Evaluation of the kinetic and thermodynamic parameters of oxidation reaction in biodiesel from a quaternary mixture of raw material/Avaliacao dos parametros cineticos e termodinamicos da reacao de oxidacao em biodiesel de uma mistura quaternaria de materias-primas

The corrosion parameters such as activation energy ([E.sub.a]), enthalpy of activation ([DELTA]H*), and entropy of activation ([DELTA]S*) for mild steel in 1 mol [L.sup.-1] HCl solution in the absence and presence of GAI with different concentrations (10-60 ppm) at various immersion periods in the temperature range of 303-323 K were calculated and tabulated (Table 4).

where N is Avogadro's number, h is Planck's constant, [DELTA]S* is the entropy of activation, and [DELTA]H* is the enthalpy of activation.

Corrosion Inhibition of Mild Steel in 1 mol [L.sup.-1] HCl Using Gum Exudates of Azadirachta indica

The opening up of the enzyme structure is accompanied by an increase in the disorder, randomness or entropy of activation. The values of thermodynamic parameters were calculated from Figure 3(d).

Solid state fermentation of a raw starch digesting alkaline alpha-amylase from Bacillus licheniformis RT7PE1 and its characteristics

The results showed that the values of 6G increase with increase in temperature due to increase in salt-solvent interaction.The change in entropy of activation 6S is given by 27].

Viscosity and thermodynamic properties of alkali metal bromides in the presence of acetonitrile, 3-hydroxypropionitrile and acetonitrile + 3-hydroxypropionitrile mixture at various temperatures

The entropy of activation values in the absence and presence of inhibitor are negative.

3-methyl-4-amino-5-mercapto-1, 2, 4-triazole as corrosion inhibitor for 6061 Al alloy in 0.5 M sodium hydroxide solution

[DELTA][S.sup.*] = entropy of activation, J [mol.sup.-1];

Enthalpy and entropy of activation decreased, while the Gibbs free energy increased with increased temperatures for the range shown in Table 5.

Mathematical modeling of the drying process of corn ears/Modelagem matematica do processo de secagem de espigas de milho

The reactions were also studied at four different temperatures: 40, 50, 60, and 70 [degrees]C and the observed values of pseudo first-order rate constant, [k.sub.obs], were used to calculate the activation parameters of the various sugars, including their entropy of activation reported in Tables 3a and b.

Kinetics of oxidation of D-arabinose and D-xylose by vanadium (V) in the presence of manganese II as homogeneous catalyst

Whereas the negative values for entropy of activation indicate that the activation complex has a more ordered or more rigid structure than the reactants and the reaction is slower than the normal(17).

Synthesis and thermal analysis of some 1, 2, 4-triazole derivatives

The entropy of activation ((delta)S [?] ), enthalpy of activation ((delta)H [?] ) and free energy of activation ((delta)G [?] ) of the main exothermic decomposition reaction of ACOF corresponding to T = T po , E a = E k and A = A k are obtained by Eqs.

Thermal Behavior, Non-Isothermal Decomposition Reaction Kinetics and Thermal-Safety Evaluation on 3-Amino-4-chloroximidofurazan