n00b question about sodium

[Guest nerdster]

I've read online tutorials before about extracting sodium from rocksalt and salt...my question is, how do you melt the salt and what do you use...also...does the chlorine gas come out while you melt the salt or while you run the current through it? Is 12v 12amps enough?

 

edit: I am using a car battery charger to supply the electricity...

[jdurg]

To electrolyze sodium chloride you need to melt the salt which requires a temperature of around 1200 degrees Fahrenheit. (Or if you mix in some calcium chloride it can reduce the temperature required to melt the mixture by nearly 600 degrees). The sodium and chlorine will form once the current is put through the molten salt. At the elevated temperature, any sodium formed will be a liquid and will react VERY violently with water vapor in the air and oxygen. Therefore, you need to make sure that there is an inert, argon atmosphere over the electrolysis apparatus. Also, you have to make sure that the chlorine gas which is formed at the opposite electrode doesn't come anywhere near the molten sodium, otherwise a violent reaction will ensue. Chlorine gas is a poisonous war gas too, and it doesn't take a whole lot of it to ruin your day.

 

Don't take this personally, but based upon the title of your post and the nature of your questions, you really should not be trying to make sodium metal anyway. It will just result in bad things happening as it does not seem as though you have enough of a background in this to perform the procedure safely. (We'd hate to see a curious chemist get hurt or injured because they tried something that they weren't really prepared for).

[Guest nerdster]

Don't take this personally' date=' but based upon the title of your post and the nature of your questions, you really should not be trying to make sodium metal anyway. It will just result in bad things happening as it does not seem as though you have enough of a background in this to perform the procedure safely. (We'd hate to see a curious chemist get hurt or injured because they tried something that they weren't really prepared for).[/quote']

 

THat's almost exactly what my chem teacher told me...how much of a current do you need? I'm using a car battery charger

[Insane]

The current you are supplying is very good. Since the voltage is so low, you'll get better results if the two electrodes are closer together, which is a bad thing since non-inert gases + sodium = boom.

[raivo]

12A is enough but as jdurg said there is much more problems to solve. Even melting NaCl and holding it liquid during 5 min is not easyest thing.

[Mendelejev]

Exactly, maybe you better start with some less danger experiments, like the electrolysis of water into hydrogen and oxygen. It's a good experiment to start with becouse you can learn the principles of electrolysis and you will experience how difficult it can be. I did it some years ago and I have to say, that there were a lot of thing I didn't knew before I did that experiment (for example, adding some HCl, or NaCl to conduct current better, or how to store your gasses safely in test-tubes, ...)

 

It's also easier to use a NaCl-solution in stead of NaCl-solid ! You won't have to melt it and use fire !! But I think that you will produce chlorine and hydrogen. Not sodium becouse it has an E° that is very small. Maybe if you use a very concentrated solution of NaCl, it will work (cf. Nernst-equation) !

[jdurg]

Think about what you're saying there Mendelejev. What are the physical and chemical properties of sodium metal? What does electrolysis of an aqueous solution mean? Now you tell me how sodium metal can be formed at all based upon those conditions.

[Mendelejev]

Yes, indeed, I was thinking to theoretically ! Maybe it would work, but you're right, the sodium metal formed, would react immediately with the water and would burn heavily. I also remember my profs words : "If you want chlorine, take the solution, it's cheaper and easier. But if you want sodium, you don't have a choice, you have to melt your NaCl" !! Too bad, it would have been nice if it worked with alkali metals !!! I would buy tons of salt and make my own Sodium

[Lance]

Melting the salt is the easy part (use a plumbers torch and a brick), the hard part is getting metallic sodium. At those temperatures the sodium will react with the air almost instantly. You would have to spray the reaction with an inert gas which would make direct heating impossible. You would thus have to heat from the underside which would be much more complicated and require more heat to overcome the losses.

 

Electrolysis of NaCl is possible but if you want it to work it wont be cheap. You might as well just buy sodium off ebay.

[budullewraagh]

it's not expensive!

[Lance]

it's not expensive!

 

Splitting salt or buying sodium? I was referring to the former.

[budullewraagh]

electrolysis of molten chloride or hydroxide isnt expensive. btw, hydroxide is the way to go

[jdurg]

The heat and appartus required to melt the salt is expensive, however. You need a very hot flame and a container that can withstand the heat, as well as something to prevent the sodium from reacting.

[YT2095]

and when the reaction starts, the external application of heat is no longer required, as the electricity will do the rest

[budullewraagh]

the heat isnt very expensive. just use an acetylene torch. the apparatus? you can do it effectively with just a car battery and a torch