Enthalpies of dissolution are found for crystalline racemic tartaric and glutaric acids and isatin in water and in potassium hydroxide solutions at 298.15 K via direct calorimetry. The protolytic equilibria in isatin aqueous solutions are studied at 298.15 K and ionic strengths of 0.5 (relative to potassium nitrate) by potentiometric means. Standard enthalpies of formation are calculated for racemic tartaric and glutaric acids, isatin, and the products of their dissociation in aqueous solutions.

The enthalpies of complexation of glycine (HGly ± ) with Nd 3+ and La 3+ ions at 298.15 K and at an ionic strength of 0.5 (KNO3) are determined by means of calorimetry. The thermodynamic characteristics of the reactions of formation are calculated for NdGly 2+ , NdGly 2 + , LaGly 2+ , and LaGly 2 + complexes.

Complexation between ethylenediamine- N , N '-disuccinic acid (Н 4 Y, EDDS) and Er 3+ , Yb 3+ , and Lu 3+ ions in aqueous solutions is studied by calorimetry and pH measurements. The thermodynamic parameters (log K , Δr G , Δr H , and Δ r S ) of formation of LnY–and LnHY complexes at 298.15 K and ionic strength I = 0.5(KNO 3 ) are determined. Changes in the thermodynamic parameters of reactions while moving along the lanthanide series are discussed.

The enthalpies of complex formation of L-asparagine (HAsn±) with Nd3+ and La3+ ions are determined calorimetrically at 298.15 K and an ionic strength of 0.5 (KNO3). The thermodynamic characteristics of the formation of the NdAsn2+, NdAsn2+, LaAsn2 +, and LaAsn2 + complexes are calculated.

Thermodynamic parameters of the complex formation reactions of ethylenediamine-N,N′-disuccinic acid (H4Y) with La3+, Ce3+, Pr3+, and Nd3+ ions are determined by means of calorimetry and pH-metry in aqueous solutions at 298.15 K and ionic strength I = 0.5 (KNO3). Values of logK, Δr G, Δr H, and Δr S are calculated for reactions of LnY- and LnHY complex formation. Changes in the thermodynamic parameters of reactions in the lanthanides series are discussed.

Thermodynamic parameters of the complexation reactions between ethylenediamine-N,N′-disuccinic acid (H4Y) and Nd3+ ions at 298.15 K and ionic strengths of 0.1, 0.5, 1.0, 1.5 (KNO3) are determined by means of calorimetry and pH-metry. The values (logK, Δr G, Δr H, Δr S) of the formation reactions of NdY− and NdHY complexes are calculated at the investigated and zero values of ionic strength. The change in the thermodynamic parameters of the reactions is discussed.

The enthalpies of complexation of ethylenediamine - N, N-/ -disuccinic acid (H4Y) with Gd3+ ion were determined by calorimetric method at 298.15 K and ionic strength of 0.5; 1.0; 1.5 (KNO3). Thermodynamic characteristics of complex formation of GdY and GdHY were calculated at fixed and zero ionic strength. The obtained results were interpreted.

The thermodynamic parameters of the formation of the complexes of ethylenediamine- N , N ′-disuccinic acid (H 4 Y) with Sm 3+ ion are determined by means of calorimetry and measuring pH at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 (KNO 3 ). The values of log K , Δ r G , Δ r H , and Δ r S are calculated for the formation of SmY − and SmHY complexes at fixed and zero values of ionic strength. The resulting values are interpreted.

By potentiometric titration method at 298.15K and ionic strength of 0.2; 0.5; 1.0 (KNO3) the composition and stability of coordination compounds of zinc, nickel and cobalt with diethylenetriamine-N, N, N ', N ", N"-pentaacetic acid in aqueous solution was determined. The results were compared with literature data. The Ni2+ ions were found to form with diethylenetriamine-N, N, N ', N ", N"-pentaacetic acid complexes more stable than the ions Zn2+ which corresponds to the conventional Irving-Williams series

The enthalpies of complexation of lead(II) and cobalt(II) with N-(carboxymethyl)aspartic acid (H3Y) were determined calorimetrically at 298.15 K within a wide ionic strength range (KNO3). The thermodynamic characteristics of formation of the CoY2- and PbY2− complexes were calculated at non-zero and zero ionic strengthes. The explanation of the obtained values is given.

The constants and heat effects of complexation of N - (carboxymethyl) aspartic acid (H3L) with Cd2+ ion at 298.15 K and ionic strength values of 0.2, 0.5 and 1.0 (KNO3) were determined by the potentiometric and calorimetric methods. The thermodynamic characteristics of the reaction of CdL complexation in aqueous solutions were calculated. The values obtained were interpreted.

The enthalpies of complexation between N,N-bis(carboxymethyl)aspartic acid (H4Y) and the Pb2+ ion at 298.15 K were determined from calorimetric data for a wide range of the ionic strengths (KNO3). The thermodynamic characteristics ΔH, ΔG, and ΔS, of formation of the complexes PbHY− and PbY2− were calculated for zero and fixed ionic strengths. The results obtained were interpreted.

The equilibrium constants and heats of formation of complexes of N,N-bis(carboxymethyl)aspartic acid (H4Y) with Cd2+ ions at 298.15 K and ionic strengths of 0.2, 0.5, and 1.0 (KNO3) were determined by potentiometric titration and calorimetrically. The thermodynamic characteristics of formation of the CdY2− complex at fixed and zero ionic strength values were calculated. The values obtained were interpreted.