2 0 2009 ape man 1 journal Original Apelblat, A.[Alexander] Manzurola, E.[Emanuel] J. Chem. Eng. Data 2009 2009-02-25 Cryoscopic and Volumetric Studies in the Maleic Acid + Water System Freezing points of aqueous solutions of maleic acid were determined. They served to obtain water activities and osmotic and activity coefficients at freezing temperatures. The integration of the Gibbs-Duhem equation was performed by taking into account the dissociation of maleic acid. Densities of (0.09831, 0.4902, and 0.9790) mol * kg-1 maleic acid solutions were measured at 5 K intervals from T ) (288.15 to 333.15) K, and they are compared with the literature results. From the determined densities, the apparent molar volumes, the cubic expansion coefficients, and the second derivatives of volume with respect to temperature which are interrelated with the derivatives of isobaric heat capacities with respect to pressure were evaluated. These derivatives were qualitatively correlated with the changes in the structure of water when maleic acid is dissolved in it. 10.1021/je800357c 54 333-337 1 maleic acid C4H4O4 1 Commercial source 1 99.7 3 Stated by supplier 2 water H2O 1 Commercial source 1 99.5 3 Estimated by the compiler 1 1 2 1 Principal objective of the work RDC TRC 2/24/2009 1 Solid-liquid equilibrium temperature, K Visual observation Liquid Difference with the reference state, X-X(REF) Pure solvent at the temperature of the same phase equilibrium Liquid 2 2 Liquid Crystal 2 Pressure, kPa 101 3 1 Molality, mol/kg 1 Liquid 2 1 .001 2 1 -.003 1 1 .0014 2 1 -.004 1 1 .0028 2 1 -.008 1 1 .0051 2 1 -.014 2 1 .0075 2 1 -.021 2 1 .0106 3 1 -.031 2 1 .025 3 1 -.076 2 1 .0501 3 1 -.139 3 1 .0769 3 1 -.215 3 1 .1048 4 1 -.269 3 1 .2459 4 1 -.599 3 1 .5177 4 1 -1.168 4 1 .6946 4 1 -1.563 4 1 1.009 4 1 -2.23 3 1 1.404 4 1 -2.99 3 1 1.987 4 1 -4.05 3 1 3.085 4 1 -5.76 3 1 1 2 1 Principal objective of the work RDC TRC 2/24/2009 1 Mass density, kg/m3 Vibrating tube method Liquid Direct value, X 1 Author Liquid Pressure, kPa 101 3 1 Temperature, K 2 Molality, mol/kg 1 Liquid 2 1 288.15 5 2 .09831 4 1 1003.24 6 1 .2 1 293.15 5 2 .09831 4 1 1002.29 6 1 .2 1 298.15 5 2 .09831 4 1 1001.04 6 1 .2 1 303.15 5 2 .09831 4 1 999.59 5 1 .2 1 308.15 5 2 .09831 4 1 997.91 5 1 .2 1 313.15 5 2 .09831 4 1 996.07 5 1 .2 1 318.15 5 2 .09831 4 1 994.03 5 1 .2 1 323.15 5 2 .09831 4 1 991.81 5 1 .2 1 328.15 5 2 .09831 4 1 989.41 5 1 .2 1 333.15 5 2 .09831 4 1 986.88 5 1 .2 1 288.15 5 2 .4902 4 1 1018.5 6 1 .2 1 293.15 5 2 .4902 4 1 1017.26 6 1 .2 1 298.15 5 2 .4902 4 1 1015.79 6 1 .2 1 303.15 5 2 .4902 4 1 1014.1 6 1 .2 1 308.15 5 2 .4902 4 1 1012.25 6 1 .2 1 313.15 5 2 .4902 4 1 1010.18 6 1 .2 1 318.15 5 2 .4902 4 1 1007.98 6 1 .2 1 323.15 5 2 .4902 4 1 1005.58 6 1 .2 1 328.15 5 2 .4902 4 1 1003.01 6 1 .2 1 333.15 5 2 .4902 4 1 1000.36 6 1 .2 1 288.15 5 2 .979 4 1 1035.99 6 1 .2 1 293.15 5 2 .979 4 1 1034.47 6 1 .2 1 298.15 5 2 .979 4 1 1032.74 6 1 .2 1 303.15 5 2 .979 4 1 1030.81 6 1 .2 1 308.15 5 2 .979 4 1 1028.74 6 1 .2 1 313.15 5 2 .979 4 1 1026.46 6 1 .2 1 318.15 5 2 .979 4 1 1024.06 6 1 .2 1 323.15 5 2 .979 4 1 1021.47 6 1 .2 1 328.15 5 2 .979 4 1 1018.75 6 1 .2 1 333.15 5 2 .979 4 1 1015.92 6 1 .2