why water is one of yhe best fire extinguisher??

hydrogen is one of the best fuel,which can be fired only in the presence of oxygen.on the contrary water which is made by hydrogen ?

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korky246 years ago
Well, is just a simple characteristic property of water. You see, water is hydrogen and oxygen that was bond chemicaly, and that chemical reaction changes the properties. Another example of this is salt. Salt is NaCl, Sodium and Cloride, both of which are extreamly posionus to us, yet in this for, we call it table salt.
caarntedd7 years ago
As Redneck says, ask a fireman, so I,ll do my best. (Have I given away my secret identity?).
Water has a large capacity for absorbing heat, more than other commonly used extinguishing agents. The greater the exposed surface area of the applied water, the more rapidly it will absorb heat (hence spraying it with a nozzle of some sort). The water contacts the burning material absorbing a huge amount of heat from it, and it's temp rises rapidly turning it into steam. (If I remember correctly water expands about 1700 times as this occurs). This lowers the temp of the burning material below it's ignition point which reduces/stops combustion. It also increases the pressure in the compartment (if you are inside) which prevents oxygen from flowing in and helps to smother the fire.
And as lemonie says it's cheap and plentiful.
Also, oxygen isn't a flammable gas, it's an oxidizing agent which aids the combustion of the fuel.
I'm affraid I'm not very scientific, so maybe you should google the fire triangle (heat/fuel/oxygen) or as we call it now the fire tetrahedron (heat/fuel/oxygen/chemical chain reaction) it's pretty interesting. Firefighting is getting a bit more tech these days. Personally I just like the part where I get to run into a burning building while everybody else is running out (and driving fire engines of course).
Any other firefighters out there that can explain this better or correct my answer?
To understand how water extinguishes fire, one must first understand what fire is. Fire is the rapid chemical reaction causing emmense amounts of heat and flame. This is classified by the Fire Triangle- Fuel, Heat and Catalyst.. If you remove one of these things, the Fire goes out. This stops the chemical reaction, henc extinguishing the flame.

Water helps extinguish fire in two ways. As mentioned above, Water reduces the tempurature of the fuel, removing one of the elements of the fire triangle (fuel, heat, and oxygen). Also, if applied in large amounts, water seperates the fuel from it's catalyst, oxygen, hence removing a second arm of the triangle.

Interesting tidbit- Fire is the same chemical reaction as Rust, just a whole load quicker-

You still need the fourth element, the uninhibited chemical chain reaction, to produce sufficient exothermic reaction energy.
If you light a fire with a match and then blow the match out, you have removed the ignition source, one of the four elements. Without the chemical reaction of the fire producing it's own heat, it will go out.

Fuel+Oxygen+Ignition Source+Chain Reaction.
Any three of these elements put together does not necessarily produce fire. Put all four together and it will burn.

+1- Best answer- which I would expect from a Fireman. 

framistan7 years ago
Water is truly a MIRACLE substance.  Did you know heat RISES in water? That is true, but then why do lakes freeze on TOP?   Frozen water crystals form snowflakes.... all of them BEAUTIFUL and UNIQUE.  Hydrogen and oxygen separately are flammable. Combined they extinguish fire. Water can be a LIQUID, Solid, or a vapor depending on temperature.  A scientist in japan studied water crystals when they formed... he would say different WORDS and hatefull words formed JAGGED UGLY crystals. Words of LOVE formed pretty crystals.  I think it is a miracle substance and another miracle only God could have made.
varun saxena (author)  framistan7 years ago
dear sir,
thanx for ur important comment.
it helps me to increse my knowledge. but sir, u had written dat,
heat rises in water, and about the study of a japense scientist,
sir can u please tell me in brief about that?
it will be gr8 4 me to learn.
Yes but which "wrench" did He/She use?
caarntedd7 years ago
I don't think any of us have really answered the question. I'm not sure if I even understand it.
paganwonder7 years ago
Because water is weird.  It's componants are a fuel and an accelerent yet in a molecule they will douse a flame- weird.

But water really isn't well explained by our rules of chemistry and physics- it really shouldn't occur.

Sorry,  I didn't really answer you question.
lemonie7 years ago
It's cheap and plentiful.
Hydrogen will react with other things e.g. fluorine, so "only" isn't quite true.

Did you know that "hydrogen" means "water-former".

If I understand your question right the answer is simple and yet complex.  Water makes the best (under certain but not all conditions) extinguisher for a fire because a fire needs three things.  Oxygen-Heat-Fuel.  Using water on a fire in enough quantity removes the heat.  Now without getting into the different types of fire and its sources of fuel, you are putting H2O on the fire.  The fire needs oxygen but your not putting pure oxygen on the fire nor are you putting pure hydrogen on the fire.  Which means your not "feeding" the fire more air or fuel it needs to continue.  If this doesn't answer your question try talking to any fireman for a more in depth answer.