Yes.

http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/electrol.html

In my 7TH grade chemistry, the volume difference was basically 2 to 1 - H20

H test tube was twice as the O test tube, have to look mass up

First principles

1 Ga of water weighs 3776.103 g

1 mol of water weighs 18 g

total mols = 209.7

2 H atoms = roughly 2 g/mol total

2*209.7 = 419.4 g/Gal of water.

The more interesting bit is the volume that this takes up.

PV = nrt

V = 209.7 * 8.314 * 290 / 101.325 (these numbers may be wrong, but they should be close...)

V = 5000 L

I got about 523 liters when I did the calculation. Are you off by a factor of 10, or am I?

22.4 liters per mole at STP X 23.3 moles H₂ per gallon of H₂O = 523 liters.

I had 210 moles of water in 1 gallon -- maybe that's where you went wrong. There's only 23.3 moles H2 in 1 gallon of H₂O.

with further thinking...i am pretty sure you are wrong. It takes 210 moles of h2 and 105 moles of O2 to get 210 moles of h2o. I think what you are doing is trying to take a ratio of sorts, but that should only be used for weight...(i think).

2g h2/18 g of h2o = 11.111% of 3kg = 419 g of hydrogen.

2g/mol = M of H2

so

419/2 = 210 moles of h2.

210*22.4 = 4700 L

You are saying that in 3kg of water, there is only 46.6 g of h2 and i am pretty sure that is incorrect.

You're right. Roughly 5 cubic meters of H2.

I trust that the original poster realizes that the energy value of those 5 cubic meters will be less that the energy value of the electricity used to do the electrolysis.

Substantially.

You have the correct answer.

HI Everyone,

Thanks for the replies. I have enough information to be dangerous now.

Thanks for the info.

ECUDesigner

Wow! Either 500 liters or 5000 liters that seems like a lot of hydrogen.

Once you have done this what is left over? Oxygen?

Let me know,

ECUDesigner

Yes, oxygen is left over. H2 comes off the negative electrode, and O2 comes off the positive electrode. Of course, pure water is hard to hydrolyze, so adding a little salt is sometimes necessary, so it (whatever kind it may be) would be left over.

'Tis true. I've been involved with chemists and biologists around the university here who have asked me to specify deionization systems for water.

Self-ionization of water is rather complex, but Wikipedia has a good treatise on the process.

the answer is simple multiplication. 1800 gallons of hydrogen{mostly, but other volatile gases}in 1 quart of water, 4 quarts of water in 1 gallon 4x1800gallons=x hydrogen is also over 3 times as energy as gasoline per gallon.

Huh?!

You're comparing gallons of gas (a strange measure) against gallons of liquid. Use mass.