Could water become explosive if heated enough?

[jeebs]

First off I have to say that I'm not much of a chemist, so there's probably something elementary I've missed here. This weird little question just popped into my head, and it goes as follows:

water is oxygen and hydrogen, right? and it has a boiling point of 100 Celsius. But, if I'm not mistaken, if we have it in a sealed container we can keep putting energy in, keep heating it up. presumably almost indefinitely.

Would there come a point where the temperature gets so high that the water molecules break apart and the H and O parts exist on their own, so that if you were to suddenly rip the container open and make a spark, the gases would rush out and combust, seeing as hydrogen burns in oxygen?

if not, why not?

 

[Borek]

If water was heated up to decompose, gases are hot enough to not react back before they get cold. But when temperature goes down they will react back creating water, unless they were earlier separated.

 

[jeebs]

ahh, well, there goes that dream...

 

[turbo]

First off I have to say that I'm not much of a chemist, so there's probably something elementary I've missed here. This weird little question just popped into my head, and it goes as follows:

water is oxygen and hydrogen, right? and it has a boiling point of 100 Celsius. But, if I'm not mistaken, if we have it in a sealed container we can keep putting energy in, keep heating it up. presumably almost indefinitely.

Would there come a point where the temperature gets so high that the water molecules break apart and the H and O parts exist on their own, so that if you were to suddenly rip the container open and make a spark, the gases would rush out and combust, seeing as hydrogen burns in oxygen?

if not, why not?

Your limitation here is physics and engineering, not chemistry. If you confine water in a sealed container and keep adding energy, you will create a destructive steam explosion when the vapor pressure in the vessel exceeds the strength of the containment. That's why boilers have safety relief valves among other things.

 

[DDTea]

Apparently water can detonate by a very different mechanism.

I read about it from Sam Barros's site, but have not gotten around to investigating it more. Kind of interesting, though. http://www.powerlabs.org/waterarc.htm

 

[Dr Lots-o'watts]

...Would there come a point where the temperature gets so high that the water molecules break apart and the H and O parts exist on their own, so that if you were to suddenly rip the container open and make a spark, the gases would rush out and combust, seeing as hydrogen burns in oxygen?

Instead of raising the temperature, you can simply run a current through the water and catch the two gases in upside down test tubes. It's a common elementary experiment.

http://en.wikipedia.org/wiki/Electrolysis_of_water

 

[hawkingfan]

Actually, water can become explosive if you heat it enough. At around 2000 degrees Centigrade, it decomposes to hydrogen and oxygen. At even higher temperatures around 6000 K, it becomes a plasma. (a high temperature ionized gas that's electrically neutral) Then as you get to around 10,000 to 15,000 degrees, hydrogen nuclei can fuse together to make helium and this is a highly exothermic reaction. (it's what generates heat in stars) The sudden release of large amounts of heat will cause a huge explosion as the plasma increases it's pressure and expands as a result of the temperature change. Stars don't begin to collapse in on themselves until their nuclear fuel runs out so this should give you an idea on how strong the pressure produced by nuclear fusion is.

So technically, yes you can make water explosive by heating it enough. You can actually make any two light elements explosive by heating them as long as they fuse to produce an element with an atomic number smaller than 26. (stars die and collapse in on themselves after iron is made since the making of iron by fusion is highly endothermic)

 

[Borek]

Then as you get to around 10,000 to 15,000 degrees, hydrogen nuclei can fuse together to make helium

You are off by several orders of magnitude.

 

[Kevin VdM]

The energy needed to remove an electron from hydrogen is 13.6 Electron Volt.
Converting electron volt to kelvin:

(1ev/Kb) = (1.60217653 X 10^-19 J)/(1.3806505 X 10^-23 J/K) = 11604,505 K

13.6 * 11604,505 K = ~158 000 degrees Kelvin.

 

[DDTea]

The energy needed to remove an electron from hydrogen is 13.6 Electron Volt.
Converting electron volt to kelvin:

(1ev/Kb) = (1.60217653 X 10^-19 J)/(1.3806505 X 10^-23 J/K) = 11604505 K

13.6 * 11604505 K = ~158 000 000 degrees Kelvin.

This result is high by a factor of 10,000; it should be 15 800 K .

 

[Kevin VdM]

Wow i just recalculated, there is indeed a hughe error in my formulla.
I'm off with a factor of 1000 i think.
1Ev = 11604,505 K

So 13,6Ev is somewhere around 158 000 K
I think this should be a correct result.