VE - Excess Volumes, Mixture Densities

The data bank DDB-VE contains a large amount of mixture densities and excess volumes. Excess volumes represent the deviation from ideal mixing volume and are crucial for describing the effect of pressure on the real behavior (activity coefficients and fugacity coefficients).

The figure on the right shows the excess volume for the well known system ethanol-water as function of liquid mole fraction for several different temperatures. As the excess volume is negative, one can expect to yield a smaller volume of the mixture than the sum of the pure component volumes when mixing pure ethanol and water. At room temperature mixing of 1 dm3 each of water and ethanol will lead to only 1.92 dm3 of mixture.

In case of immiscible liquids, the size of the immiscible region can be influenced by pressure as the system would shift to the state of lower volume upon pressure increase. In case of negative excess volumes, applying sufficient pressure often leads to complete miscibility. This can be a great advantage e.g. in case of chemical reactions, where the reaction rate is limited by the transport through the phase boundary.

A full list of systems is available in our DDB Online Search system. The page might take some seconds to load because of its size.

Selected Scientific Papers (Experimental Data)

2010    Solubility and density measurements of palmitic acid in supercritical carbon dioxide + alcohol mixtures    Brandt L., Elizalde-Solis O., Galicia-Luna L.A., Gmehling J.    Journal    Fluid Phase Equilib., 289, 1, 72 79 (2010)
2006    (p, rho, T) Properties and Apparent Molar Volumes Vphi of CaCl2 in Methanol at T = (298.15 to 398.15) K and Pressure up to 40 MPa    Ihmels E.C., Safarov J.T., Hassel E., Gmehling J.    Journal    J.Chem.Thermodyn., 38, 3, 224 229 (2006)
1999    Densities and Excess Molar Volumes of 14 Binary Liquid Mixtures of Normal Alkanes (C6 or C7 + C8, C10, C12, C14, C16, C18, or C20) at 313.15 K    Fischer K., Anders C., Gmehling J.    Journal    Eldata Int.Electron.J.Phys.-Chem.Data, 5, 1, 19 38 (1999)
1997    Phase Equilibria and the Excess Molar Volume of the Systems Acrylonitrile + Water, Acetonitrile + Water, and Acrylonitrile + Acetonitrile    Park S.J., Oh J.H., Choi H.J., Paek S.K., Fischer K., Gmehling J.    Journal    Hwahak Konghak, 35, 5, 678 683 (1997)
1995    Excess Molar Volumes at the 308.15 K for Constituent Binaries of n-Decane, n-Dodecane, 1-Decanol and 1-Dodecanol    Park S.-J., Gmehling J.    Journal    Korean J.Chem.Eng., 12, 2, 152 155 (1995)