Abstract

BUKLESKI, Miha  and  PETRUšEVSKI, Vladimir. The Economic demonstrator: prepare it once, use it many times. V. liquid-liquid phase transition phenomena. Educ. quím [online]. 2019, vol.30, n.1, pp.111-120.  Epub Oct 14, 2019. ISSN 0187-893X.  https://doi.org/10.22201/fq.18708404e.2019.1.65185.

A simple and economic way of conducing demonstration experiments about liquid-liquid phase transitions is presented and discussed. Pairs of liquids are sealed in a series of ampoules and each ampoule is put in a beaker filled with either ice or hot water. Depending on the nature of the components mixed, the system can become homogeneous or heterogeneous. Three kinds of systems are discussed: a system with upper critical solution temperature (UCST), with lower critical solution temperature (LCST), and a system with both upper and lower critical solution temperature.

Keywords : phase transitions; economic demonstrations; nitrobenzene; hexane; nicotine; triethylamine; Gibbs energy of mixing; demonstrations; physical chemistry.

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