Electrolysis of Water (1 Viewer)

[ubermale]

I posted this in the Chemistry forum, but got no responses so hopefully I can get help here.

For chemistry, we have to answer this question:
Describe the process of electrolysis of water using electron dot diagrams to assist your description.

I know the set up for electrolysis, i.e. battery, wires, cathode, anode, electrolyte, etc. But for this question I can't seem to explain why oxygen is produced at the anode and hydrogen at the cathode. I know it has something to do with reduction and oxidation reactions but I don't fully understand the concept.

P.S. For this question, we are assuming that sulfuric acid (H2SO4) is the electrolyte used.

Any help would be very, very much appreciated.

 

[bored of sc]

Electrolysis is chemical spliting or a decomposition reaction which, in most cases, 1 reactant breaks down to form 2 products. This is known as a chemical change. The best example to illustrate this point is water or H2O.

The chemical reaction for the electrolysis of water is:

2H20 (l) -----> 2H2 (g) + O2 (g)

The electron diagram is too hard to do through this post but Hydrogen has 1 outer shell electron and Oxygen has 6. In order for a substance/element/compund to be chemically stable in needs 2 or 8 (etc) outer shell electrons

H20 is stable because in each molecule of water 2 hydrogen atoms share each of its 1 electron with the oxygen (which has 6), so therefore 2 covalent bonds created whcih each have 8 outer shell electrons, thus making the molecule stable.

Hydrogen and oxygen are diatomic (2 atoms forming a molecule) as an uncombined element because only 1 atom each of hydrogen and oxygen only have 1 and 6 electrons in their outer shells respectively. Thus, as above, they share electrons, creating diatomic molecules.

As for the electrical attractions. Oxygens ions are a -2 charge while hydrogens ions are a +1 charge. Opposites attract, so negative oxygen is attracted to the positive anode while positive hydrogen is attracted to the negative cathode. This over simplifies it but, so don't trust me, get some year 12 chemists to look at your questions.

And the electolyte stuff - I'm not sure at all.

Hope that helps