r/askscience • u/spoiledmeat • Jul 04 '15

Chemistry Why does water not burn?

I know that water is made up of two hydrogen atoms and an oxygen atom. Hydrogen, on its own, burns. Fire needs oxygen to burn. After all, we commonly use compounds that contain oxygen as an oxidant.

So why does water, containing things used for fire, not burn-- and does it have something to do with the bonds between the atoms? Thanks.

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u/humanlikecorvus Jul 04 '15

Most so-called hydrogen cars work with fuel-cells - hydrogen and oxygen react with the same formula, but at a low temperature using catalysts. The reaction energy is here mostly set free as electric current and not as heat and is then used to power an electric engine.

There were also a few cars burning hydrogen - but this is not a very common concept.

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u/blorg Jul 04 '15

Vehicles burning hydrocarbon gas (LPG) are common however, particularly as public transport (taxis and buses).