الملخص

Abstract The study deals with the influence of temperatures and the percentage of ethanol in ethanol-water mixtures on the values of ionization constants of some oxime and phenolic acids derived from aromatic and aliphatic carbonyl compounds. These mixtures having ethanol contents in the range (25-100) percent. Determination of ionization constant values of acids under study at different temperatures facilitates the evaluation of thermodynamic parameters of acids ionization. The last prove that ionization processes of acids are nonspontaneous (+∆G), endothermic (∆+H) and accompanied by an increase of order (∆S = -). The variation of alcoholic – water ratios seen above, facilitates the a claculation of relative ionization constants (Krelative) of acid (2) as a representative compound. The study led to a conclusion of a decrease of ionization constants of acids by an increase of alcoholic contents as properly discussed.