Electrolysis of sodium chloride

[Lance]

2 NaCl + 2 H2O = 2 NaOH + Cl2 + H2

 

I’m not talking about an aqueous solution of NaCl. I'm talking about pure Molten NaCl.

[budullewraagh]

2 NaCl + 2 H2O = 2 NaOH + Cl2 + H2

where did you get THAT?

 

NaCl+H2O ->Na+ + Cl- + H2O

[AtomicMX]

(thats electrolisis)

 

And i understand, but if you try with Hg you would get it with not too much pain in the head.

[budullewraagh]

(thats electrolisis)

that isn't what happens with electrolysis. the reaction is:

2NaCl -> 2Na+Cl2

 

if you do it in water, you get NaOH, but you'd have to be incredibly stupid to do it in water.

 

also, referring to an above post where i mentioned the reactions of alkali metals with water, i'd like to post an image i found:

http://www.ulg.ac.be/lem/images/cesium.jpg

you can tell the difference between the cesium and potassium, no?

[AtomicMX]

Is not stupid if you do what i said with the mercury.

my reaction was for acouse solution.

[Lance]

that isn't what happens with electrolysis. the reaction is:

2NaCl -> 2Na+Cl2

 

if you do it in water' date=' you get NaOH, but you'd have to be incredibly stupid to do it in water.

 

[/quote']

 

Well you would probably do it in water if you wanted the hydrogen. The salt would just make the solution more conductive.

 

also' date=' referring to an above post where i mentioned the reactions of alkali metals with water, i'd like to post an image i found:

http://www.ulg.ac.be/lem/images/cesium.jpg

you can tell the difference between the cesium and potassium, no?[/quote']

 

I don't get it... what's the question?

[AtomicMX]

Lance, but you can get the sodium with an electrolisis of salt in water.

 

If you want to get it, i can tell you how.

[Lance]

also' date=' sodium doesn't react all that dangerously with water. depending on how much you add the sodium will fizz around the surface and hydrogen will be released. potassium has a similar effect but it is more vigorous and it burns in a purple flame.[/quote']

 

Yes it will only explode if the reaction gets hot enough to ignite the hydrogen produced.

[Lance]

Lance' date=' but you can get the sodium with an electrolisis of salt in water.

 

If you want to get it, i can tell you how.[/quote']

 

Yes well I was thinking of making allot of Sodium hydroxide first then electrolyzing that... But I have already wasted so much time and energy this way...

[AtomicMX]

Oh! i see.

[AtomicMX]

How high does the temperature can arise with that plumer.... stuff torch..?

[Lance]

How high does the temperature can arise with that plumer.... stuff torch..?

I'm not sure I understand the question. How hot does the torch get? I couldn't really say. It burns propane but the temperature would be determined by the air: gas ratio.

[budullewraagh]

the delta [math]HF_2_5[/math] a C in a CH3 and the C in a CH2 is 88. we have 2 of those bonds in propane. for CH-H it is 106. for CH2-H it is 113 + or - 1.

propane is C3H8.

 

88*2+(2*106)+(6*113)=1066

of course, it takes energy to form the bonds in our new H2O and CO2.

[math]HF_2_5[/math] of OC=O is 127.2 + or - 0.1

for HO-H it is 119.2 + or - 0.2

(6*127.2)+(8*119.2)=1716.8

looks endothermic, no?

it isn't.

the [math]HF_2_5[/math] for O2 is 119.11

10*119.11=1191.1

(1191.1+1066)-1716.8=540.3

 

these energy values can be found in Lange's Handbook of Chemistry. for some odd reason it did not indicate a unit of measurement for these values. perhaps it's calories/mole. at room temperature, the specific heat ratio for air is 1.401. if so, the delta heat in celcius is 385.6531049. of course that doesn't sound like enough. if the measurement were in kilocalories, it would be far too great. so, if anybody could lend me a hand on the conversion factor of that measurement and/or what unit it is in i would be most grateful.

[Lance]

Nice work... I would also be interested in the end result.

[YT2095]

Lance: instead of using pencil "lead" as it`s quite thin and fragile and contains alot of clay, when you go to the welding shop for Argon, look for some gauging rods, buy a few of those, and peel the thin copper coating off, underneath will be pure compressed carbon and much thicker

 

also an iron/steel based can wont react with the sodium, it`ll be quite safe, you`re quite right though, if it was an Alu can, then you could have problems!

molten sodium is used in nuclear reactors as a heat exchange/coolant, I`m fairly sure it`s in steel pipes also

 

keep up the good work!

[raivo]

There is one problem that no one mentioned so far. Boiling point of sodium is 883 C -thats to near to 800. Even if you can melt NaCl not heating it more than just needed your sodium will evaporate more rapidly than acetone at room temperature. Also it will oxidise almost instantly. When they produce sodium they make mixture of 42% NaCl and 58% CaCl to get melting point 505 C.

 

Most convenient way to make sodium at home is probably by electrolysis of sodium chloride in some solvent that will not react with sodium. While it may be not very easy do get those solvents it does not need any heating or fast piking of sodium metal.

[budullewraagh]

it wouldn't work; molten sodium would fly out of the mixture. also, the solvent would boil

[YT2095]

Most convenient way to make sodium at home is probably by electrolysis of sodium chloride in some solvent that will not react with sodium. While it may be not very easy do get those solvents it does not need any heating or fast piking of sodium metal.

please state the solvent, or at least A solvent that would do as you suggest, as far as I know there ARE NON, that goes for the chem industry as well, so we`de ALL like to hear what it is pleeeeeze

[budullewraagh]

i have some other good methods of sodium production:

Na2CO3 can be reduced with charcoal or coke, finely powdered iron, sulfur, aluminum or magnesium. Al, Mg, Ca, CaH2, CaSi or CaC reduce NaCl to Na at high temperatures. Finely powdered iron, ferrosilicon, calcium carbide or coke yield sodium from the fused hydroxide. the silicate, sulfide, sulfate and cyanide can also be reduced to sodium at high temperatures.

 

Na2CO3+2C -> 2CO+Na2O

CO2+C -> 2CO

Na2O+C -> 2Na+CO

delta h=-231kcal/mole

 

refer to:

http://www.sciencemadness.org/library/sodium-production.pdf

[raivo]

Russians at 1950...1970 studied methods of making alkaline metals by electrolysis of non aqueous solutions. They did not get it quite for production because this method is like other metal plating and works well only with small currents. So its slow. Papers about those experiments are quite hard to find now. Some i still got. First experiments they did were with acetone. I do not know what salt they used but results where not satisfactory because acetone must be very cold not to react with Na too fast. Next they experimented with propylene carbonate (that is now used as electrolyte in lithium batterys, also as solvent in some desodorants) as solvent for NaClo3 and sayd that "sodium plating" they got with this solvent was of best quality. They also succeeded in making potassium this way. One more solvent they used was pyridine ( C5H5N ) for NaCl. It gave good results but is toxic. Dimetylformamide was also mentioned somewhere. This is almost all data i have. IMO this is at least worth experimenting because it may be much easyer and safer way to make alkaline metals in small lab.

 

It may be that many other and easyer-to-get solvents will also do the work but problem is that most anorganic salts will not dissolve in organic solvents. (This is why we can not use molten candles as electrolyte)

 

I try to buy propylene carbonate and maybe pyridine from my chemist soon and then we will see what happens.

[Lance]

I just realized, there is no need for argon... helium is much easier to find and just as inert. When I get some more funds I’m going to go up the party store and rent a tank of helium.

 

Arg... I also just realized, they probably add oxygen to the gas to prevent kids from suffocating themselves... bummer.

[YT2095]

be carefull, those tanks are only a percentage Helium, the rest is air! I know, because I asked B.O.C about it, and they told me that party use stuff is only about 30% IIRC

[brokenbin]

It wouldn't work because then the electrolysis result would be sodium ion rather than sodium metal. The only way to do is, accroding to my science book, heat NaCl up until it melts, and then apply electricity to it. Then there would be melted sodium in one side and clorine gas in the other.

 

By the way, you can electrolyse water and NaCl by using a very strong megnet, such as a megnet from a computer hard drive.

[brokenbin]

Hey people, check this site out:

http://www.public.asu.edu/~jpbirk/ CHM-115_BLB/Chpt20/sld107.htm

it tells you how to electrolyse NaCl

[YT2095]

By the way, you can electrolyse water and NaCl by using a very strong megnet, such as a megnet from a computer hard drive.

erm... can you support that claim in any way?

I for one don`t think that`s even remotely possible, even with a NIB magnet from a HDD.

 

I`de like to be proven wrong though, as that would open up a whole new field of Science for me