water and fire?

Question

ok, in order to set things on fire you need energy (matches or something) and O2 (oxygen)..

so why wont water fire when we light it?? water consists of Oxygen????

Answer 1

You need three things for combustion to take place. Heat, an oxidizer and fuel. Normally we think of the fuel as having carbon it (wood, oil, gas, etc.), the oxidizer is oxygen from the air and the heat source can be the flame from a match, etc.

Water is not a fuel, it is not an oxidizer and it does a great job of adsorbing heat, reducing the temperature. While water is made up of hydrogen and oxygen, it is hydrogen (a great fuel) and oxygen (a great oxidizer) that have already burned and released their energy. There is no free oxidizing source in the water. That's the general answer to your question.

Two interesting points about fire.

Heat is a key component. What happens if you put a match under a huge fire log? The match burns down and the log doesn't light. Why? The log has too much thermal mass and the localized temperature didn't get high enough to light the log on fire even though there was plenty of fuel and oxygen. That's why we use kindling, smaller pieces of wood that will heat up to combustion temperatures more easily.

There are some cases where water will appear to support combustion. Pure sodium metal in water will react violently. The sodium is so unstable that it will split water to use the oxygen as an oxidizer. This releases hydrogen gas and the resulting hydrogen and air mixture combined with the heat from the sodium reacting can cause a fire or explosion. Not really common, but it can happen!

Answer 2

the scientific way to say it is that the hydrogen bonding holding the oxygen together is to strong for the oxygen to excape into a combustion reaction (fire) plus your missing a key ingredient carbon and or fuel (an example of it working would i guess be a oil slick where the oil on the top of the water burns slightly better) hope that explained it

Answer 3

Because it's not really oxygen anymore when it mixes with hydrogen. Gaseous oxygen is needed for a flame and the energy needed is heat. My best guess would be that the energy needed for a flame exits the material (water) and conducts into the surrounding objects and materials.
Also you need fuel.

Answer 4

Yes, water molecules contain Oxygen, in combination with two Hydrogen atoms. This creates a different substance (namely water) which displays different properties to Oxygen on its own (the most obvious being that it's a liquid at room temperature, not a gas).

Answer 5

When water touches fire the fire goes out

Answer 6

Oxygen in water is bonded to hydrogen. It can neither burn nor support combustion.