Q210: Atomic Spectra – Colored Balloon Explosion

Introduction

Balloons filled with hydrogen and containing metal salts are ignited.  When the balloon explodes, the characteristically colored flame for that metal is seen.

2H2(g) + O2(g) → 2H2O(g)

To Conduct Demonstration

  1. Caution the audience to cover their ears and to expect a loud explosion.  Wear earplugs if desired.
  2. Light the candle on the end of the yardstick and lower the lights.
  3. Bring the candle under the balloon until the tip of the flame touches the balloon.  Be prepared for an explosion.  Do not light the string on fire!

Salts

Cupric Chloride
Lithium Chloride
Stronium Chloride
Cupric Sulfate
Boric Acid
Borax (Sodium Borate)
Calcium Chloride
Potassium Chloride
Sodium Chloride
Sodium Carbonate

Safety 

This is best performed outside or in a very large lecture room.  The explosions can shoot out salt particles, and the resulting smoke can be irritating.  Hearing damage can occur with especially large balloons.

Acknowledgment

Phil Ogata, Spring 1992