Abstract: This study aims to provide a new thermodynamic method for determining the value of Drago's four interaction parameters, namely Ea, Eb, Ca, and Cb (kcal1/2 mol-1/2). The method is based on the following fundamental novelties:

The values of the parameters Ea, Eb, Ca, and Cb are simultaneously determined for seven amphoteric substances. Thus, there are a total of 28 values to be determined, with each set consisting of seven substances. For the seven selected amphoteric substances, there are seven equations of the type:

V∂2h / n = (Ea Eb + Ca Cb)

Next, all possible 2-to-2 combinations of these seven substances are generated. For each 2-to-2 combination, one of the two is selected as a solute (2) and the other as a solvent (1), or vice versa. By measuring the mixing energy, ΔEmix (2.1), of these combinations, the 21 measurements available to extract the energy, ΔEint, of chemical bonds, according to the enclosed Buchmann paper:

ΔEmix (2.1) = (Ea1 Eb2 + Ca1 Cb2) + (Ea2 Eb1 + Ca2 Cb1)

Next, the seven equalities of the type V∂2h / nj = (Eaj Ebj + Caj Cbj) (kJ / mol) with j = 1,7 are put together with 21 equalities of the type ΔEint = (Eaj Ebj+1 + Caj Cbj+1) + (Eaj+1 Ebj + Caj+1 Cbj). This will generate a system comprising 28 equations for 28 unknown parameters. The resolution of this system will afford the 28 sought values of Drago’s four parameters Ea, Eb, Ca, Cb for the seven selected substances.

Keywords: Mixing energy, chemical interaction energy, Hansen's solubility parameters, Drago's interaction parameters, orthogonal matrix of experiments.

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Abstract: The mechanism and kinetics are developed for the free-radical nonbranched-chain initiated formation of ethylene glycol in methanol–formaldehyde solutions at formaldehyde concentrations of 0.1–3.1 mol dm–3 and temperatures of 373–473 K. The experimental concentrations of the free unsolvated form of formaldehyde are given at the different temperatures and total concentrations of formaldehyde in methanol. The experimental dependence of the radiation-chemical yields of ethylene glycol on formaldehyde concentration in γ-radiolysis of methanol–formaldehyde solutions at 373–473 K is shown. At a formaldehyde concentration of 1.4 mol dm–3 and T = 473 K, the radiation-chemical yield of ethylene glycol is 139 molecules per 100 eV. The effective activation energy of ethylene glycol formation is 25 ± 3 kJ mol–1. The quasi-steady-state treatment of the reaction network suggested here led to a rate equation accounting for the non-monotonic dependence of the ethylene glycol formation rate on the concentration of the free (unsolvated) form of dissolved formaldehyde. It is demonstrated that the peak in this dependence is due to the competition between methanol and CH2=O for reacting with adduct radical HOCH2CH2O•.

Keywords: Methanol, Formaldehyde, Formation, Ethylene Glycol, Radiation-Chemical Yield, Rate Equation.