<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0187-893X</journal-id>
<journal-title><![CDATA[Educación química]]></journal-title>
<abbrev-journal-title><![CDATA[Educ. quím]]></abbrev-journal-title>
<issn>0187-893X</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Facultad de Química]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0187-893X2019000100111</article-id>
<article-id pub-id-type="doi">10.22201/fq.18708404e.2019.1.65185</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[The Economic demonstrator: prepare it once, use it many times. V. liquid-liquid phase transition phenomena]]></article-title>
<article-title xml:lang="es"><![CDATA[El demostrador económico: prepáralo una vez, úsalo muchas veces. Fenómenos de transición fase V. líquido-líquido]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Bukleski]]></surname>
<given-names><![CDATA[Miha]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[Vladimir]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Ss. Cyril and Methodius University Faculty of Natural Sciences and Mathematics Institute of Chemistry]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Republic of Macedonia</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Ss. Cyril and Methodius University Faculty of Natural Sciences and Mathematics Institute of Chemistry]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Republic of Macedonia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>00</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>00</month>
<year>2019</year>
</pub-date>
<volume>30</volume>
<numero>1</numero>
<fpage>111</fpage>
<lpage>120</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0187-893X2019000100111&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0187-893X2019000100111&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0187-893X2019000100111&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract 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.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Se presenta y discute una forma sencilla y económica de realizar experimentos de demostración sobre transiciones de fase líquido-líquido. Los pares de líquidos se sellan en una serie de ampollas y cada ampolla se coloca en un vaso lleno de hielo o agua caliente. Dependiendo de la naturaleza de los componentes mezclados, el sistema puede volverse homogéneo o heterogéneo. Se discuten tres tipos de sistemas: un sistema con temperatura de solución crítica superior (UCST), con temperatura de solución crítica más baja (LCST) y un sistema con temperatura de solución crítica superior e inferior.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[phase transitions]]></kwd>
<kwd lng="en"><![CDATA[economic demonstrations]]></kwd>
<kwd lng="en"><![CDATA[nitrobenzene]]></kwd>
<kwd lng="en"><![CDATA[hexane]]></kwd>
<kwd lng="en"><![CDATA[nicotine]]></kwd>
<kwd lng="en"><![CDATA[triethylamine]]></kwd>
<kwd lng="en"><![CDATA[Gibbs energy of mixing]]></kwd>
<kwd lng="en"><![CDATA[demonstrations]]></kwd>
<kwd lng="en"><![CDATA[physical chemistry]]></kwd>
<kwd lng="es"><![CDATA[transiciones de fase]]></kwd>
<kwd lng="es"><![CDATA[manifestaciones económicas]]></kwd>
<kwd lng="es"><![CDATA[nitrobenceno]]></kwd>
<kwd lng="es"><![CDATA[hexano]]></kwd>
<kwd lng="es"><![CDATA[nicotina]]></kwd>
<kwd lng="es"><![CDATA[trietilamina]]></kwd>
<kwd lng="es"><![CDATA[energía de la mezcla Gibbs]]></kwd>
<kwd lng="es"><![CDATA[demostraciones]]></kwd>
<kwd lng="es"><![CDATA[química Física]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Atkins]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[de Paula]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<source><![CDATA[Physical Chemistry]]></source>
<year>2006</year>
<edition>8th edition</edition>
<page-range>185-7</page-range><publisher-loc><![CDATA[London, UK ]]></publisher-loc>
<publisher-name><![CDATA[Oxford University Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Baloska]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[V. M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Economic Demonstrator: Prepare it Once, Use it Many Times. IV. Ni[HgI4] - a Thermochromic Salt. Chemistry]]></article-title>
<source><![CDATA[Bulgarian Journal of Chemical Education]]></source>
<year>2010</year>
<volume>19</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>440-3</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bukleski]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[V. M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Preparation and Properties of a Spectacular Thermochromic Solid]]></article-title>
<source><![CDATA[Journal of Chemical Education]]></source>
<year>2009</year>
<volume>86</volume>
<numero>1</numero>
<issue>1</issue>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Campbell]]></surname>
<given-names><![CDATA[A. N.]]></given-names>
</name>
<name>
<surname><![CDATA[Kartzmark]]></surname>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Heats of mixing and dielectric constants of some partially miscible liquid pairs]]></article-title>
<source><![CDATA[Canadian Journal of Chemistry]]></source>
<year>1969</year>
<volume>47</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>619-23</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Campbell]]></surname>
<given-names><![CDATA[A. N.]]></given-names>
</name>
<name>
<surname><![CDATA[Kartzmark]]></surname>
<given-names><![CDATA[E. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Falconer]]></surname>
<given-names><![CDATA[W. E.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The System: Nicotine-methylethyl Ketone - Water]]></article-title>
<source><![CDATA[Canadian Journal of Chemistry]]></source>
<year>1958</year>
<volume>36</volume>
<numero>11</numero>
<issue>11</issue>
<page-range>1475-86</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Christensen]]></surname>
<given-names><![CDATA[S. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Donate]]></surname>
<given-names><![CDATA[F. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Frank]]></surname>
<given-names><![CDATA[T.C.]]></given-names>
</name>
<name>
<surname><![CDATA[LaTulip]]></surname>
<given-names><![CDATA[R. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Wilson]]></surname>
<given-names><![CDATA[L. C.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Mutual Solubility and Lower Critical Solution Temperature for Water + Glycol Ether Systems]]></article-title>
<source><![CDATA[Journal of Chemical and Engineering Data]]></source>
<year>2005</year>
<volume>50</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>869-77</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dickman]]></surname>
<given-names><![CDATA[A. G.]]></given-names>
</name>
<name>
<surname><![CDATA[Stell]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A globally accurate theory for a class of binary mixture models]]></article-title>
<source><![CDATA[Molecular Physics]]></source>
<year>2002</year>
<volume>100</volume>
<numero>18</numero>
<issue>18</issue>
<page-range>3021-8</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flaschner]]></surname>
<given-names><![CDATA[O.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[LXXXI. - The miscibility of the pyridine bases with water and the influence of a critical-solution point on the shape of the melting-point curve]]></article-title>
<source><![CDATA[Journal of the Chemical Society, Transactions]]></source>
<year>1909</year>
<volume>95</volume>
<page-range>668-85</page-range></nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flaschner]]></surname>
<given-names><![CDATA[O.]]></given-names>
</name>
<name>
<surname><![CDATA[MacEven]]></surname>
<given-names><![CDATA[B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[XCVI. The Mutual Solubility of 2-Methylpiperidine and Water]]></article-title>
<source><![CDATA[Journal of the Chemical Society, Transactions]]></source>
<year>1908</year>
<volume>93</volume>
<page-range>1000-3</page-range></nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Glasstone]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<source><![CDATA[Textbook of Physical Chemistry]]></source>
<year>1975</year>
<edition>2nd edition</edition>
<page-range>556-9</page-range><publisher-loc><![CDATA[Beograd, Serbia ]]></publisher-loc>
<publisher-name><![CDATA[Nau&#269;na Knjiga]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Johnson]]></surname>
<given-names><![CDATA[M. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A Demonstration of the Continuous Phase (Second-Order) Transition of a Binary Liquid System in the Region Around Its Critical Point]]></article-title>
<source><![CDATA[Journal of Chemical Education]]></source>
<year>2006</year>
<volume>83</volume>
<numero>7</numero>
<issue>7</issue>
<page-range>1014-6</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McKelvy]]></surname>
<given-names><![CDATA[E. C.]]></given-names>
</name>
<name>
<surname><![CDATA[Simpson]]></surname>
<given-names><![CDATA[D. H.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Equilibria in the Systems Carbon Disulfide : Methyl Alcohol, and Carbon Disulfide : Ethyl Alcohol]]></article-title>
<source><![CDATA[Journal of the Americal Chemical Society]]></source>
<year>1922</year>
<volume>44</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>105-15</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Logan]]></surname>
<given-names><![CDATA[S. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Behavior of a Pair of Partially Miscible Liquids]]></article-title>
<source><![CDATA[Journal of Chemical Education]]></source>
<year>1998</year>
<volume>75</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>339-42</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Monkovi&#263;]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[V. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Bukleski]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Economic Demonstrator: Prepare it Once, Use it Many Times. I. Continuous Thermochromism in the NO2-N2O4 System - Equilibrium Shifts Induced by Temperature Changes. Chemistry]]></article-title>
<source><![CDATA[Bulgarian Journal of Chemical Education]]></source>
<year>2006</year>
<volume>15</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>256-64</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Moore]]></surname>
<given-names><![CDATA[W. J.]]></given-names>
</name>
</person-group>
<source><![CDATA[Physical Chemistry]]></source>
<year>1975</year>
<edition>2nd edition</edition>
<page-range>119-20</page-range><publisher-loc><![CDATA[Beograd, Serbia ]]></publisher-loc>
<publisher-name><![CDATA[Nau&#269;na Knjiga]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Patterson]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Role of free volume in polymer solution thermodynamics]]></article-title>
<source><![CDATA[Pure and Applied Chemistry]]></source>
<year>1972</year>
<volume>31</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>133-49</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Patterson]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Polymer compatibility with and without a solvent]]></article-title>
<source><![CDATA[Polymer Engineering and Science]]></source>
<year>1982</year>
<volume>22</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>64-73</page-range></nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Patterson]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<name>
<surname><![CDATA[Robard]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<source><![CDATA[Thermodynamics of Polymer Compatibility Macromolecules]]></source>
<year>1978</year>
<volume>11</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>690-5</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[V. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Bukleski]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Stojanovska]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Economic Demonstrator: Prepare it Once, Use it Many Times. II. Continuous Thermochromism in Aqueous Solutions of Transition Metal Chlorides. Chemistry]]></article-title>
<source><![CDATA[Bulgarian Journal of Chemical Education]]></source>
<year>2007</year>
<volume>16</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>20-8</page-range></nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[V. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Bukleski]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Economic Demonstrator: Prepare it Once, Use it Many Times. III. Phenomena of Discontinuous Thermochromism. Chemistry]]></article-title>
<source><![CDATA[Bulgarian Journal of Chemical Education]]></source>
<year>2008</year>
<volume>17</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>109-17</page-range></nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Senland]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
<name>
<surname><![CDATA[Pettitt]]></surname>
<given-names><![CDATA[B. M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Binary Solution Critical Opalescence]]></article-title>
<source><![CDATA[Journal of Chemical Education]]></source>
<year>1995</year>
<volume>72</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>560-4</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stojanovska]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Petru&#353;evski]]></surname>
<given-names><![CDATA[V. M.]]></given-names>
</name>
<name>
<surname><![CDATA[&#352;optrajanov]]></surname>
<given-names><![CDATA[B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Concept of Sublimation - Iodine as an Example]]></article-title>
<source><![CDATA[Educación Química]]></source>
<year>2012</year>
<volume>23</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>171-3</page-range></nlm-citation>
</ref>
<ref id="B23">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Yalkowsky]]></surname>
<given-names><![CDATA[S. H.]]></given-names>
</name>
<name>
<surname><![CDATA[He]]></surname>
<given-names><![CDATA[Y.]]></given-names>
</name>
<name>
<surname><![CDATA[Jain]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[Handbook of Aqueous Solubility Data]]></source>
<year>2010</year>
<publisher-loc><![CDATA[Boca Raton, USA ]]></publisher-loc>
<publisher-name><![CDATA[CRC Press]]></publisher-name>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
