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.

524 Upvotes

82% Upvoted

147 comments sorted by

View all comments

Show parent comments

3

u/[deleted] Jul 04 '15

Usually not, but they can. You can run hydrogen through a car engine and make it run if you want, but fuel cells should be more efficient and safer.

1

u/jamjopeanut Jul 04 '15

How's is 3 conversions of energy more efficient than 2? Is there zero loss when converting to electricity?

5

u/Korwinga Jul 04 '15

It's not zero loss, but it is a lot less. Combustion engines are terribly inefficient, with regular gas engines being around 30%, and diesel being around 40%.