Burning Candle - Combustion Process

Purpose

To demonstrate features of the burning process and to debunk myths about this supposedly well-known demonstration.
 

Equipment

Burning candle apparatus with colored water.

 

Setup Time

5 min.
 

    Images

    i1-64

    Description

    A common pre-college experiment is to burn a candle inside of a bottle which has been turned upside down over a container of water. The water supposedly rises about one-fifth of the way up the bottle, indicating that the oxygen, about one-fifth of the air in the atmosphere, has been "used up" in the combustion process. The candle in our experiment is placed inside the sealed tube containing air above a colored water bath, and is then ignited by a hot wire. The water level goes down initially, then returns to its original level just after the candle goes out. There is NO CHANGE in the water lev
     

    References

    Lecture Demonstration Formula Sheet. John H. Rosengren, Old Experiment - New Twist, Elementary School Science Bulletin,nationa Science Teachers Association, November 1962, pages 10-11.