5E40.30 - Battery - Avalanche Voltage

Code Number:
5E40.30
Demo Title:
Battery - Avalanche Voltage
Condition:
Excellent
Principle:
Electrode Materials in Acid Solutions and Current Flow
Area of Study:
Electricity & Magnetism
Equipment:
Flash bulbs, magnesium and copper electrodes, beaker, sulfuric or hydrochloric acid, tube clamp, and stand.
Procedure:

Connect the flash bulb to the copper and magnesium electrodes. Pour a small amount of FRESH sulfuric acid into the beaker and insert the copper electrode.  Quickly inserting the magnesium electrode will trigger the flash bulb showing a substantial current flow.

NOTE: Works with any acid that sustains a high density current flow.  If fresh sulfuric acid is not available you may use hydrochloric acid in its place.

References:

Bassam Z. Shakhashiri, Chemical Demonstrations Vol. 2, University of Wisconsin Press, 1985, p. 109.
 

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.