Apparent molar volumes and apparent molar heat capacities of aqueous urea, 1,1-dimethylurea, and N,N′-dimethylurea at temperatures from (278.15 to 348.15)K and at the pressure 0.35MPa

Thermodynamics of the first and second proton dissociations from aqueous l-aspartic acid and l-glutamic acid at temperatures from (278.15 to 393.15)K and at the pressure 0.35MPa: Apparent molar heat capacities and apparent molar volumes of zwitterionic, protonated cationic, and deprotonated anionic forms at molalities from (0.002 to 1.0)mol·kg−1

“…Table 11 gives the results of these calculations. It can be seen from table 11 that the values obtained for TABLE 8B Regression parameters of equation (4) for apparent molar heat capacities C p,/ (T, m) of {H 2 Glu ± (aq)}, {H 2 Glu ± (aq) + HCl(aq)}, {H 2 Glu ± (aq) + NaO-H(aq)}, {H 3 Glu + Cl À (aq)}, and {Na + HGlu À (aq)} c i H 2 Glu ± (aq) observed, w = 0 (table 5B) {H 2 Glu ± (aq) + HCl(aq)} observed, w = 1 (table 6B) {H 2 Glu ± (aq) + NaOH(aq)} observed, w = 1 ( We can compare the effects of simple substitutions on V / and C p,/ obtained here and in our other recent works [6][7][8][9][64][65][66] with those of the exhaustive study of Cabani et al [67]. We note that the comparisons we make cover results obtained over broader ranges of T and m than those used by Cabani et al as noted in tables 11 and 12.…”

“…We note that the comparisons we make cover results obtained over broader ranges of T and m than those used by Cabani et al as noted in tables 11 and 12. Our average value for DV / (H-CH 3 ) from this and our other works [7,8,64,65] is (16.0 ± 1.2) cm 3 AE mol À1 , which compares to the value of 15.80 cm 3 AE mol À1 from reference [67]. Our average value for DV / (H-COOH) from the current investigation is (10.3 ± 5.4) cm 3 AE mol À1 , which compares to the value of 20.34 cm 3 AE mol À1 from reference [67].…”

“…b Molality of HCL. The ± uncertainties are from propagation of uncertainties as described in reference [65]. a Molality of L-glutamic acid with stoichiometric molality ratio {m(HGlu)/m(HCl)} = 0.997 5 .…”

Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, d-sorbitol, and xylitol at temperatures from (278.15 to 368.15)K and at the pressure 0.35MPa

“…Aqueous solutions were prepared from each compound as received from the manufacturers as follows: adonitol {CH 2 OH-CHOH-CHOH-CHOH-CH 2 OH, Fluka, product number 02240, lot number 437283/1, 1.00 mass fraction by HPLC, molar mass M 2 /(g AE mol À1 ) = 152.1464, CAS Registry 488-81-3, density q c /(g AE cm À3 ) = 1.4}, dulcitol (CH 2 OH-CHOH-CHOH-CHOH-CHOH-CH 2 OH, Sigma, product number D0256, 1.00 mass fraction by GC, M 2 = 182.1725, CAS 608-66-2, q c = 1.49), glycerol (CH 2 OH-CHOH-CH 2 OH, Anachemica, product number 43567-320, lot number 301023, 0.999 mass fraction by assay, M 2 = 92.0942, CAS 56-81-5, q c = 1.26), meso-erythritol (CH 2 OH-CHOH-CHOH-CH 2 OH, Sigma, product number E7500, 1.00 mass fraction by GC, M 2 = 122.1203, CAS 149-32-6, q c = 1.45), myo-inositol (C 6 was determined by combustion. This analysis verified that the nominal purities given above by the manufacturer are within ±0.003 mole fraction of the true values.…”

“…As a continuation of our earlier work in obtaining thermodynamic data of aqueous solutions [1][2][3][4][5], and more recently with organic compounds in aqueous solution [6][7][8][9], we report the apparent molar volumes V / and apparent molar heat capacities C p,/ of aqueous solutions of adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol. These seven sugar alcohols are similar in structure, offering an opportunity to evaluate thermodynamic properties in terms of solute structure.…”