Decay Kinetics of UV-Sensitive Materials: An Introductory Chemistry Experiment

• Garrhett Via ^[1] ; Chelsey Williams ^[1] ; Raymond Dudek ^[1] ; John Dudek ^[2]
  1. [1] Wittenberg University

     Wittenberg University

     City of Springfield, Estados Unidos

     
  2. [2] Hartwick College

     Hartwick College

     City of Oneonta, Estados Unidos

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 92, Nº 4, 2015, págs. 747-751
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • First-order kinetic decay rates can be obtained by measuring the time-dependent reflection spectra of ultraviolet-sensitive objects as they returned from their excited, colored state back to the ground, colorless state. In this paper, a procedure is described which provides an innovative and unique twist on standard, undergraduate, kinetics experiments. Specifically, UV-sensitive beads and threads are utilized as the time changing system, as opposed to more conventional wet chemical systems. The spectral data is collected and analyzed by the students during a standard laboratory session, and the class results are pooled so that the reflection spectra and decay curves of all colors for both UV sensitive beads and threads can be compared. This new approach to a kinetics experiment increases student interest in a safe, inexpensive, and environmentally friendly way.