Gelatin and the Tyndall Effect: A Colorful and Tasty Demonstration

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 6 Issue 2 (2001) pp 95-96

Gelatin and the Tyndall Effect: A Colorful and Tasty Demonstration

Mark A. Benvenuto

Department of Chemistry and Biochemistry, University of Detroit Mercy, 4001 W. McNichols Rd., Detroit, MI 48219-0900
Received May 23, 2000. Accepted July 30, 2000

Published online: 16 February 2001

Abstract. This demonstration is a safe and nontoxic example of the Tyndall effect that utilizes common, even edible, materials. A glass of gelatin and a laser pointer are used to illustrate the Tyndall effect. Laser light is scattered when it is shone through a colloidal gelatin dispersion. At least two glasses of gelatin are aligned so that students can see scattering through the first glass, then a lower overall intensity of scattered light through the second glass. Variations of the demonstration are presented, such as shining the laser light through a glass of salt water to show the effect as the salt dissolves.

Key Words: In the Classroom;

(*) Corresponding author. (E-mail: benvenma@udmercy.edu)

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Supporting Materials:

s00897010464b.mpg (MPEG movie) (16.1 MB) 10.1007/s00897010464b