How does splitting water move oxygen and hydrogen?

Hi Jayden,

Water is composed of two atoms of hydrogen and one of oxygen hence its chemical formula of H2O.
In liquid water some of it forms ions (charged atoms) H+ and OH- called hydrogen ion and hydroxyl ion respectively.

If you apply a voltage across water the current carries the positive ions (H+) to the negative electrode and the negative ions (OH-)are attracted to the positive electrode. (Opposites attract in electricity and magnetism).

Thus at one electrode H+ picks up an electron to become H. One H will react with another to give H2 (hydrogen gas).

At the opposite electrode a slightly more complex process occurs as follows. OH- and OH- lose electrons to become 2OH these two recombine to give H2O an O. The O then combines with another to give O2 or oxygen gas.

So at one electrode you get hydrogen and at the other oxygen.

I hope this helps.
Best wishes,


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Thermodynamics, chemistry, chemical reactions, kinetics, chemical reaction safety, dust explosion technology, static electricity. General science.


Over 40 years experience as a practicing thermochemist in industry. Head of the fire and explosion laboratory of a major European chemical company (Ciba-Geigy). Now retired.

Institute of Chemical Engineers. Royal Society of Chemistry.

Chartered Chemist, Member of the Royal Society of Chemistry (C.Chem MRSC). Msc Sheffield.

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