While these crash course videos cover topics relevant to the US SAT and UK GCSE's, some of their content is at a higher level (AP). So if you're studying for the SAT or GCSE's, don't worry too much about the more advanced maths, just focus on the key facts.
The electric current breaks apart the water molecules (H2O) into oxygen (O2) and hydrogen gas (H2).
At the negatively charged cathode, a reduction reaction takes place, with electrons (e−) from the cathode being given to hydrogen cations to form hydrogen gas (the half reaction balanced with acid):
Reduction at cathode: 2 H+(aq) + 2e− → H2(g)
At the positively charged anode, an oxidation reaction occurs, generating oxygen gas and giving electrons to the anode to complete the circuit:
Oxidation at anode: 2 H2O(l) → O2(g) + 4 H+(aq) + 4e−
State symbols used in chemical equations:
(g) means gas
(l) means liquid
(s) means solid
(aq) means aqueous solution or dissolved in water
An equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge are the same for both the reactants and the products. In other words, the mass and the charge are balanced on both sides of the reaction.