# Home-made way to detect lye in solution

I believe that electrolysis of salt water creates lye ($\ce{NaOH}$ - sodium hydroxide). In salt water, there's $\ce{Na+}$, $\ce{Cl-}$, $\ce{H+}$ and $\ce{OH-}$ as of ionts.

So at cathode, you get $\ce{Na2}$ and that should react with water into $\ce{NaOH}$.

I want to test, if this is true - how do I do it with household items? The solution didn't react with aluminium.

• I found more general question asking about measuring pH using household items. – Tomáš Zato Aug 31 '14 at 22:52
• The aluminium probably did not react because of its highly shielding oxide layer. – tschoppi Aug 31 '14 at 23:04
• I scratched it. I think the solution is not concentrated at all. I've left a drop on my skin and nothing happened. – Tomáš Zato Aug 31 '14 at 23:06
• A will filter out the copper chloride and procceed with electrolysis. – Tomáš Zato Aug 31 '14 at 23:06
• Where did you make copper chloride now? This is starting to confuse me... – tschoppi Aug 31 '14 at 23:14

The ions you actually get from your reaction is a higher concentration of $\ce{Na+}$ and $\ce{OH-}$, due to the fact that you are removing $\ce{H2}$ and $\ce{Cl2}$ (from $\ce{H+}$ and $\ce{Cl-}$ ions respectively) via the performed electrolysis. Under no circumstances would you generate a $\ce{Na2}$ species, you would rather write it as $\ce{2Na}$. Also, in aqueous solutions the $\ce{NaOH}$ most certainly dissociates. So speaking of the formation of solid $\ce{NaOH}$ from $\ce{Na}$ in water is quite a stretch.
• So what happens to $\ce{Na+}$ ionts when I dry the water? I don't think I'm gonna get pure sodium... – Tomáš Zato Aug 31 '14 at 22:46