Ions or Molecules? Polymer Gels Can Tell
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Brett Criswell [1]
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[1] Department of Chemistry, Central Columbia High School, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 83, Nº 4, 2006, pág. 576
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
Principles of chemical bonding are fundamental to the content of any introductory chemistry course. Part of the discussion of these principles normally entails making the distinctions between ionic and covalent compounds. Often students are shown the macroscopic manifestations of these distinctions in the form of an investigation of conductivity differences between these two classes of compounds. This activity offers another way to allow students to see the impact that these differences have on the properties of materials representing the two classes. Students prepare a gel by combining the superabsorbent polymer sodium polyacrylate and water, then split the gel into several piles. Samples of chemicals representing the two piles are then sprinkled onto each pile. If the chemicals are ionic in nature (or ionizable in water), they cause the gel to break down; if they are covalent in nature, they have no effect on the gel.
