# Hydrogen and oxyger

1. Oct 13, 2004

Hydrogen and oxygen

hi, ive been torturing my chem teacher recently with questions i have that she has no idea about lol but i would really like to know, i think im just going to list the qeuestions, i really dont know the answers or where to find them so if you could show me how or where you found out that would be cool

1. What is the rate of production of Hydrogen and oxygen from H2O? does it depend of the amount of voltage used in the process? if so, how?

2. what is the maximum pressure of the production of Hydrogen and oxygen, fo example, if i covered a bottle with a baloon, as hydrogen and oxygen are produced, they fill the ballon and as the baloon strached, pressurem inside the ballon increces, is there a point where that pressure actually stops the hydrogen and oxygen from being produced? again, does it depend on voltage used?and if so how?

3. how much force is produced by a certain amount of hydrogen/oxygen /spark explosion per gram of hydrogen and oxygen, im looking for an equesion here.

4. (this one isnt really about hydrogen and oxygen but i cant figrue it out) what is a malable substance that cunducts heat badly? somthing along the lines of rubber but takes a long time to heat up

I think thats all, if you could explain the answers to me id appreciate it, this is basically for a model jet engine

Last edited: Oct 13, 2004
2. Oct 14, 2004

### MaximumTaco

1) It actually depends on the current, because current is the rate at which charge is moved. If you know current, you can find moles of electrons moved per second, and you can find the rate of the reaction.

If you look up the actual redox potentials for the reactions that occur, you need a certain minimum voltage but that is it.

3. Oct 14, 2004

so if i soposivly go over taht minumum voltage, lets say by 50000 volts, nothing different should happen? how do i measure currnt and what exactly is it?

4. Oct 15, 2004

### GCT

I'll answer the first question for now.

The rate of production depends on the temperature among other things, it is related to the free energy of formation (opposite sign) at the specific temperature, you can speed up the rate "by adding work" that is inducing voltage (try researching over the internet the electrolysis of water, this process if frequently used to generate a ionic current, facilitating other reactions). In your text you should find a diagram (in the electrolysis chapter) outlining the relationship between free energy and voltage (although this is not directly pertinent to your question, it helps to understand this aspect). Overall, inducing a voltage, which you may see from the nernst equation, changes the ratio of products/reactants at equilibrium.......meaning that the relative rates of the forward and reverse reactions have changed, in favor of the formation of hydrogen and oxygen (I'm pretty sure of this), in this case (since accordance to free energy, the formation of water is favored, unless under deviant temperatures).

5. Oct 15, 2004

### GCT

Efficiency is important for this question, and I'm quite sure you don't have equipment nor the voltage energy needed to cause a balloon to explode. I'm not quite sure about the quantitative details, nevertheless, if it does not explode, other reactions, facilitated by the free energy will occur in favor of this reaction, since you have effectually provided enough activation energy for other reactions to occur; this negates activation energy as a limiting factor.

It's not a matter of force is you don't provide the intricate details of the situation.......the shape of the object on which the energy is being exerted, etc

You'll need to explain this further, in detail, to someone who is experienced in model jet engines, a chemist probably will not be able to help you adequately in this area. In fact, if you wish to pursue this endeavor, find a professional, you'll get a lot more done.

Again, you have asked very vague questions, regarding theoretical aspects, you need to work on being specific.

6. Oct 15, 2004

### chem_tr

Yes, GCT is right about finding a more qualified person about this, especially an engineer, as he/she would be more helpful than a chemist as the question involves fluid mechanics, etc, which seems more familiar to engineers.

7. Oct 16, 2004

### Bystander

MT gave you what you need to know --- you are limited by current density for various electrode materials and conditions, but the bottom line is current.

Not bad for HS --- yes, the cell potential depends on the pressures (activities) of the gases being produced (or consumed if you run it as a fuel cell). I ain't gonna give you a course in electrochemistry --- from here you hit "Nernst equation" in the encyclopedia, or Google, or whatever you like for snooping information. The standard potential is a function only of temperature, but the actual cell potential is a function of standard potential and activities.
I'm going to assume you mean "energy" rather than force --- free energy of formation of water (vapor) is around 400 kJ/mol, little more for liquid. The "force" you get depends on how you go about handling the reaction.
Modelling clay, play dough, bread dough --- you might try restating what you're trying to do --- poor heat conductor, or high heat capacity, or both?

(snip)

8. Oct 18, 2004

wow, i just realised how little i know about chem thanks, ig uess lol, ok well lets see, ill go backwards, what i meen by poor heat counductor is, well say you were wearing this thing, it would be mallable, and the heat would have to be veryhigh for a while before you fealt the heat. ok so #3 now, im assuming that when hydrogen and oxygen gas are ignited there is an explosion, or flame or whitchever, if im wrong about this i have a lot of work to do, but what im asking it the amount of force produced, how much bang for my buck so to speak, if i had it inside of an internal coumustion engine, gasolene produces X amount of forse, hydrogen (and oxygen) produce Y amount of force, this is what im getting at, some way to compare explosions and the forse produced by them. #2, i still have no propper way of phrasing this but i will give an example, i boil water in a beaker, the apor goes into a tube and drips into an open beaker, if i hold my hand over that open beaker, i notice the water stops boiling, physical or chemical change occouring it is still production of a gas and is there a certain pressure where that gas cannot be produced? what other info would be needed to answer this, im looking for equasions mostly. #1, s wait a second, rate of production depends on tempurature? so it shoudl be produced the same speed at vlts as 5000000 volts? providing tempurature is the same? i really cant look at the equasions now, ill try though. ok well this has given me a lot to reserch during my 3 AM caffene high so im gonna go for it, gracias

P.S. i thin im gonna show this post to my chem teach, hi Miss. Gambi!

9. Oct 18, 2004