Your Safer Source for Science

Since 1977

Address P.O. Box 219 Batavia, IL 60510
Phone 800-452-1261
Fax 866-452-1436
Email flinn@flinnsci.com
firewatch

Watch as the sun sets over a chemical reaction! The reaction of sodium thiosulfate with hydro chloric acid produces elemental sulfur, which precipitates from solution to form a colloidal mixture. When the reaction is carried out on an overhead projector, the light from the projector is scattered by the colloidal sulfur particles and produces a multicolored chemical sunset.

Concepts

  • Colloids
  • Light Scattering
  • Tyndall Effect