Products of Electrolysis of NaCl

I have gone online to see many times that the electrolysis of $\ce{NaCl}$ dissolved in water produces Lye:

$$\ce{2NaCl + 2H2O -> 2NaOH + H2 + Cl2}$$ Other times $\ce{NaClO3}$ or some other compound. I just want to know with one solid answer (anyone), what does this reaction produce?

Thank you.

Answer

The one solid answer is that everything you've heard is right, given the appropriate conditions.

If the cathode and anode spaces are properly separated with a porous membrane or a salt bridge, then it is just like that:

$$\ce{2NaCl + 2H2O -> \underbrace{2NaOH + H2}_{cathode} + \underbrace{Cl2}_{anode}}$$ If they are not, then the products inevitably mix with each other and react further: $$\ce{2NaOH + Cl2 -> NaCl + NaClO + H2O}$$ or, at elevated temperatures, $$\ce{6NaOH + 3Cl2 -> 5NaCl + NaClO3 + 3H2O}$$ See, chemistry is diverse. Oh wait, and there are more options. Think of the mercury cell.