Freeing Elemental Sodium from NaOH (I just had to post it...)

[NightHawkIL]

After seeing the sticky thread in this part of the forum I had to speak up...

 

First some safety: The experiment described uses corrosive chemicals and mixtures capable of burning without presence of atmosphere. It should be done outdoors in cotton clothing as fire protection, with chemically resistant gloves, and of course lab goggles. In case of fire, wait for initial reaction to subside, then use a class D extinguisher - do not attempt to put out fires with sand or water.

 

A recent experiment of mine involved the production of the highly reactive element sodium from sodium hydroxide and another less reactive metal, in this case magnesium. The reaction is as follows:

 

2Mg + 2NaOH = 2MgO + 2Na + H2

 

The magnesium (finely powdered) first ignites burning in atmospheric oxygen contained in the reaction vessel. This initial reaction produces enough energy to initiate the primary reaction. The Mg has enough desire for the oxygen contained in the NaOH to actually rip it from the hydroxide group, freeing hydrogen gas and sodium. The reaction is violently exothermic. More than enough energy is released to ignite the hydrogen gas which burns as the reaction progresses. The sodium is produced in a liquid state due to the temperature of reaction, and some of it vaporizes giving the flame a strong orange/yellow color.

 

To keep the sodium from burning immediately upon production, a loose fitting lid is placed over the reaction vessel, allowing the burning hydrogen to escape, but sealing the vessel off from atmosphere once completed. The lid is then not removed until the reaction cools to air temperature, at which point mineral oil should be added to the resulting slag to prevent further oxidation of the product.

 

Presumably this experiment could be preformed with other metals acting upon the hydroxide group, such as aluminum - in fact, I've heard aluminum gives a better yield because of a lower reaction rate and temperature which vaporizes much of the Na using Mg. I have not yet tried it. It is also quite likely that this process could free most if not all metals from their hydroxides because the reaction does not involve the metal contained in the hydroxide, but the hydroxide group alone. All hydroxides should therefore be susceptible to separation via magnesium and possibly aluminum. I will conduct further experimentation in warmer weather.

 

Here is a video of the experiment being conducted:

 

Ideally, purification and removal of the sodium from the MgO slag would be as simple as heating the mixture under mineral oil to the melting point of sodium, at which point it would gather together. So far I have been unable to do that successfully. It is possible the products needed to be heated longer or they needed to be more finely ground beforehand to free the sodium, again, more experiments will be preformed in warmer weather.

 

Just thought I would let you all in on this very simple synthesis for highly reactive metals.

 

- Ben (NightHawkInLight)

---

Merged post follows:

Consecutive posts merged

I had not read through the entire stickied thread to see that someone had already posted my videos, and that they were deemed inappropriate for this site. Feel free to remove this thread if that is so.

Edited February 4, 2010 by NightHawkIL
Consecutive posts merged.

[elementcollector1]

Oh, cool! I was just doing this today and yesterday!

Anyway, I just got my impure mixture, and you say to grind it up and heat under oil?

IT SHALL BE DONE, GOOD SIRRAH.