Floating Plastics: An Initial Chemistry Laboratory Experience
-
-
[1] Universidad Nacional de General Sarmiento
Universidad Nacional de General Sarmiento
Argentina
-
- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 78, Nº 4, 2001, pág. 522
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
-
Resumen
Chemists routinely prepare a great variety of solutions. Sometimes it is necessary to confirm that the intended product was obtained. This may be done by measuring physical properties such as absorbance, electrical conductivity, melting point, boiling point, osmotic pressure, and density. This experiment is an initial experience for introductory chemistry courses, illustrating density by application in flotation-based techniques for identification and separation of plastics. Students prepare a series of solutions with gradually increasing densities. Then they are given plastic samples of known and unknown composition and they estimate the densities of the samples by observing in which solutions they float and in which they sink. These densities are used to identify the plastics. This experiment can be linked to discussions of recycling issues and industrial applications such as identification, classification, and separation of materials.
