Solid-Liquid and Liquid-Liquid Equilibrium in the Formamide-Acetophenone System.

0091622 - UCHP-M 20070350 RIV CZ eng J - Journal Article
Malijevská, I. - Sedláková, Zuzana - Řehák, K. - Vrbka, P.
Solid-Liquid and Liquid-Liquid Equilibrium in the Formamide-Acetophenone System.
[Rovnováha kapalina-pevná fáze v systému formamid-acetofenon.]
Collection of Czechoslovak Chemical Communications. Roč. 71, 9 (2006) , s. 1350-1358. ISSN 0010-0765
Institutional research plan: CEZ:AV0Z40720504
Keywords : solid-liquid equilibria * liquid-liquid equilibria * metastable
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 0.881, year: 2006

Solid-liquid (s-l) and liquid-liquid (l-l) equilibrium was determined in the binary system formamide-acetophenone. The s-l equilibrium was measured by recording time-temperature cooling and warming curves. The l-l equilibrium was obtained in a wide range of temperatures by turbidity method. A considerable supercooling preceding solidification made it possible to examine metastable l-l equilibrium yet at temperatures lower than the solidus ones. Activity coefficients evaluated from the stable region of l-l equilibrium were correlated by Novák’s modification of the Wilson equation. Calculation of the s-l equilibrium was performed with the obtained parameters. Heat capacity of solid and liquid acetophenone was measured and its dependence on temperature is given. The transition enthalpy between two solid modifications of acetophenone is also given.

Byla měřena rovnováha kapalina–pevná fáze a kapalina–kapalina v systému formamid-acetofenon. Rovnováha kapalina-pevná fáze byla vyhodnocována z křivek chladnutí a tání. Rovnováha kapalina-kapalina byla studována pomocí zákalové metody. Díky hlubokému podchlazení byla získána řada dat rovnováhy kapalina-kapalina v metastabilní oblasti – dokonce i pod teplotou solidu. Aktivitní koeficienty byly počítány, z dat získaných měřením rovnováhy kapalina-kapalina, pomocí Novákovy modifikace Wilsonovy rovnice. Pro acetofenon byly měřeny tepelné kapacity a entalpie přechodu mezi dvěmi pevnými modifikacemi.
Permanent Link: http://hdl.handle.net/11104/0152171