Makarov D.M.

EFFECT OF PRESSURE ON EXCESS THERMODYNAMIC CHARACTERISTICS OF WATER + FORMAMIDE MIXTURE

Using the experimental data on the densities at atmospheric pressure and compressibil-ity coefficients, k=(Vo-V)/Vo, of water + FA mixture the changes in the following thermody-namic parameters were calculated under the pressure increase up to 100 MPa within the tem-perature range from 288.15 to 323.15 K: excess molar Gibbs energy, ΔPo→PGmE, excess molar entropy ,ΔPo→PSmE, and excess molar entropy ΔPo→PHmE. It was established that ΔPo→PGmEvalues were negative over the whole concentration range and minima appeared on ΔPo→PGmE= f(x2) functions at x2≈0.33. The pressure growth up to 100 MPa resulted in ΔPo→PGmE absolute values increase within entire concentration and temperature intervals. The changes in entropy component, -(ΔPo→PTSmE), of ΔPo→PGmEvalues were almost canceled by the enthalpy component changes. Minimal values of ΔPo→PSmE corresponded to x2≈ 0.33, exactly at that composition 2Н2О-FA associate formed.

2016, Т. 59, № 6, Стр. 28-36

INFLUENCE OF PRESSURE ON EXCESS THERMODYNAMIC CHARACTERISTICS OF WATER + ETHYLENEDIAMINE MIXTURE

The variations of excess molar thermodynamic characteristics: Gibbs en-ergy ΔP0→PGmE, entropy ΔP0→PSmE and enthalpy ΔP0→PHmE for the mixture of water + eth-ylenediamine in the temperature range of 288.15-323.15 K and pressures increase up to 100 MPa were calculated. Concentration dependences of ΔP0→PGmE, ΔP0→PSmE и ΔP0→PHmE versus mole fraction of ethylenediamine (x2) at all values of pressure studied were characterized by the presence of maxima. A correlation of the mixture melting diagram and change in excess molar entropy from concentration ( Po→pSmE=f(x2)) was found.

Key words: water, ethylenediamine, non-electrolytes mixtures, high pressure, excess thermody-namic parameters

2016, Т. 59, № 2, Стр. 13-18
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