actually, water splits easier when some electrolyte (i.e. HCl) is added..... pure water is a poor conductor of electricity.

The fundamental thermodynamics issue here is this:

(1) H2O + E --> H2 + 1/2 O2
(E=energy, electric in this case ) this step needs energy input

(2) H2 + 1/2 O2 --> H2O + E
this step produces energy, heat energy

E in equations (1) and (2) above are of same magnitude!!

There is no net energy gained because the energy (E) used to split water will be regained by recombining H2 and O2....which will be used again to split water........and so on........

So where does the energy to perpetually run the engine come from? battery? but the engine must work first to charge the battery after the initial charge is used up! Hmmm

Hess' Law?

Originally posted by mazdamazda
but you also need VERY pure water. not just your ordinary distilled water which is still isn't 100% pure. contamination of any sort will make the reaction impossible.