Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: oxidations

Learn more physics!

Most recent answer: 04/01/2008
great site, i have pretty much 3 questions i hope you can help me with. if you burn hydrogen, i know it creates h2o, but is any hydrogen or oxygen lost to like heat or into the void? like if you did electrolysis of h20 into a closed container and ignited the hydrogen w/ the oxygen, would it turn back into the same exact quanity of h20 as before the orginal electrolosis, which could be repeated indefinatly for eternity? what would happen if you ignited hydrogen without oxygen? i dont think gasoline contains oxygen, is this introduced when burning, or can it burn without an oxidizer aswell? (its interesting ive read that on the sun theres hot fusion of hydrogen, and that theres some byproduct like helium which is weird cause its a different element i dunno (might of read it wrong) but if the sun had oxygen wouldnt it create water vapour which would rise and freeze in space and thered be some milky way of ice, maybe thats how theres water and life on earth, hahaha im getting carried away and i guess the suntemp is almost a parrallel to absolute zero). if you ignited liquid hydrogen, would there be more explosive force as compared with regular hydrogen? thanks, interested in any feedback.
- Chris (age 20)
vancouver, canada
question 1. There's no deep intrinsic reason for any of the O2 or H2 to be lost. In practice some will be, but not much if the apparatus isn't leaky. That's a contrast to the energy balance. The work put in to electrolyze the water will always be bigger than the work gotten back from the reaction, for fundamental thermodynamic reasons.

2. Ordinary burning of either hydrogen or gasoline requires oxygen. The carburetor or fuel injector on a car is designed to mix in just the right amount of oxygen from air. The burning in the Sun is of an entirely different type. It consists of nuclear reactions, making new types of atoms. Ordinary burning is a type of chemical reaction, in which fixed types of atoms recombine into different types of molecules.

3. I'm not sure- it depends on the oxygen concentration. Too much hydrogen actually suppresses the explosion. I've seen, however, liquid oxygen react explosively with some ordinary solvent, probably acetone.

Mike W.

(published on 04/01/2008)

Follow-up on this answer.