How come water can extinguish fire???

Question

Water is made up of atoms of hydrogen and oxygen. Hydrogen is combustible while oxygen supports combustion then how it extinguish fire????

Answer 1

Hydrogen (H2 gas) on its own is combustible. Oxygen (O2 gas) is a reactant for the combustion reaction (it participates in the reaction as a fuel). But water as a liquid (H2O) is a completely different substance from hydrogen or oxygen. When two elements are chemically bonded to form a compound, they would lose their properties and the compound will gain different properties depending on how the atoms are arranged in the compound. The heat supplied by a normal fire does not provide enough energy to separate the two elements in water, so you will never experience an explosion whenever you dump water on a fire.

When you pour large amounts of water on a fire, the normally colder water would absorb the heat generated by the fire, which is an exothermic reaction (it gives energy out), usually becoming water vapour (steam). This would remove the energy required for the fire to continue burning, and so would extinguish the fire.

Answer 2

The oxygen and hydrogen molecules in water are chemically bonded to one another. You have to add a tremendous amount of energy, causing an endothermic reaction to separate them.

There are three ways to put out a fire. (Remember, fire is an oxidation process).
1) Remove the fuel.
2) Decrease the temperature of the fire so that it no longer supports combustion.
3) Remove the available oxygen.

Water accomplishes steps 2 & 3.

Answer 3

Think of water as hydrogen that is already been burned. Water on a non-electrical fire will act as a heat sink, which inhibits the heating of the fuel (on of the elements of the fire triangle) and the energy required to achieve the activation energy of the fuel. The heat will also vaporize some of the water into steam, lowering the local concentration of oxygen (another element of the fire triangle).

Answer 4

Look at sodium chloride (NaCl). Either of those chemical alone is dangerous...but together, they're not. It's table salt.

It takes a LOT of energy to separate the water into it elements, and its not something that would typically happen with a fire, anyway.

Water puts out fires primarily by cooling the fuel. It can also cut down on the available oxygen as it boils and turns in to steam (minor effect at best), or if the water is sprayed as a fog, like some fire hose nozzles do.

Answer 5

The water smothers the flame. It prevents oxygen from reacting with the fuel.

Fires are generally not hot enough to seperate the oxygen and hydorgen bonds, but some fires are and the fire department has to use CO2 or chemicals to put them out.

Answer 6

fire needs heat, fuel and oxygen.
This triangle is broken when 1 or more of these is removed.
If you type into your browser fire extinguishers you will see different fires use different retardents.
ie petrol gas etc one type,
electrical another type,
solids eg. wood grass etc another
Some use water some foam some powder.
You can smother or remove the oxygen,
cool remove the heat or
remove the fuel whatever the fire is burning.

Answer 7

Fire needs oxygen. The water moves the oxygen from the fire so it dies. The temperatur of the burning object is lowered, burnung is dicouraged.

Answer 8

the molecule is connected by a strong bond and since they are connected they don't have the characteristics of hydrogen or oxygen.

Answer 9

when two type of elments that is oxy and hydro combine to form water they lose all there individual properties and form a new compound which is water which has a new and unique properties

in simple terms when u mix all the 7 colours of spectrum(VIBGYOR) u get black. black does even look like any of the colours in spectrum.

got it........

Answer 10

well actually you cant put all fires out with water!