A wax fire

Fire

Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....

is created when melted or boiling wax is doused in water. The following reaction creates a large fireball or enlarges the flame of the already existing fire incredibly. Only a small amount of wax and water is needed to create a wax fire.

Physics Behind The Reaction

Following the basic rules of the fire triangle

Fire triangle

The fire triangle or combustion triangle is a simple model for understanding the ingredients necessary for most fires.The triangle illustrates a fire requires three elements: heat, fuel, and an oxidizing agent . The fire is prevented or extinguished by removing any one of them...

, for a reaction to take place three ingredients are required: oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

, fuel, and heat. In the case of wax melted down, only the top surface has access to oxygen, so the fire progresses slowly. When water is added to the wax, two things happen. Firstly, the water being more dense than wax, sinks to the bottom of the container. Secondly, as burning wax quickly reaches a temperature of well over 200 degrees C, the water instantly vapourises. When water changes from a liquid to a gas, there is more than a thousand-fold increase in volume. The water expands violently, and throws the hot wax layer above it in to the air as small droplets. The wax now has a much bigger surface area exposed to oxygen so combustion takes place very quickly.

For similar reasons, water should never be used to extinguish burning grease or fat, which both behave similarly to wax. Water is ineffective at putting out other flammable liquid fires, but in most liquids (e.g. petrol), the water remains as a liquid, and spreads the fire by allowing the liquid to float and burn on top of it. One should instead use baking soda to extinguish a wax fire.

See also

• Wax boiling Also known as wax burning
  Wax burning
  Wax burning , also known as wax boiling, is the heating of candle wax to high temperatures in a container as a form of entertainment.Most of the time, it refers to a local tradition of Hong Kong youths during the Mid-Autumn Festival period in public parks or other such areas...
  
  
• Chip Pan Fire
• Boilover
  Boilover (fire)
  A Boilover type of fire refers to an extremely hazardous situation where an attempt is made to extinguish semi-enclosed oil or petrochemical fueled fire with water. The hazard results due to the difference in density between oil and water...
  
  

External links

• http://www.physicsforums.com/archive/index.php/t-83794.html
• http://www.angliacampus.com/education/fire/secondar/fire.htm