Chemistry of Firefighting & Composites Julia, Nina, and Nicole

The Chemistry of Firefighting 20,000 people die in uncontrolled fires in North America each year Firefighters in the U.S. were called out on 362,500 house fires in 2009, which caused 12,650 injuries, 2,565 fatalities and $7.6 billion in property damage People need to know how to put out these fires properly There are 3 ways to extinguish a fire: 1.Cooling the fuel 2.Cutting off the supply of oxygen 3.Trapping the combustion intermediates

The Chemistry of Firefighting Cont. Class A Fire- A fire in which the fuel is a solid Class B Fire- A fire in which the burning material is a liquid or gas Class C Fire- A fire involving an electrical current Class D Fire- A fire in which a metal is burning

Cutting off the Oxygen Supply 2NaHCO₃(s) + heat Na₂CO₃(s) + H₂O (g) + CO₂ (g)

Halons Halons- a class of fire extinguishing agents that are used in automatic sprinkling systems to protect sensitive electronic equipment Used in computers and aircraft fire extinguishers Puts out fire quickly leaving no residue

What class of fire is a tree when it’s burning, and how do you put it out? Class A, Water

Composites Composites are made by embedding fibers in a plastic base (these fibers include glass, graphite, or synthetic fabrics like nylon) They are less dense than metals They are non-corrosive They absorb vibrations well Made up of two or more materials

Benefits/Uses of Composites Weigh less Cars made of composites use less fuel They are stronger and more protective Composite cars are quieter and smoother riding They do not rust

Fiberglass and Lumber Fiberglass was one of the first composites to be manufactured Lumber is the newest composite being manufactured o It can be cut and nailed o It is stronger than real wood

Name 3 Benefits of Using Composites Saves money Not heavy Stronger/safer

Homework What are 5 composites in your house? Classify these fires: A wooden picture frame Grease fire A metal pole A telephone wire If there is a kitchen fire with your gas stove why shouldn’t you cool the fire by pouring water on it?