Is it practical to make Sodium Hydroxide

[NATT]

Bros lemme know that is it practical to make Sodium hydroxide in home and if yes, plz lemme know how to do it...If not it will b a sad factor

[Theophrastus]

Personally speaking, while there are methods for synthesising sodium hydroxide, I find that given its low cost (I can get 3kg of crystallized NaOH, for around $17), it's a lot simpler (and cheaper, in terms of the reagents required in synthesis from scratch), to just buy it. You can even attain it at most hardware stores under the common name of lye, or lye crystals; something of that sort.

 

Most methods of synthesis used, are electrochemical, and generally, to achieve an adequate yield, require immensely high voltages, and quite great risk. The most common industrial method is the chloroalkali process which is, the elctrolysis of a salt solution, yielding chlorine gas and sodium hydroxide. While this is a well- known method, it is not one that can be used by amateur chemists, due to the high voltages required to attain sufficient yields, and the large quantities of chlorine gas produced. For the integrity of this forum, don't try such a method in full, unless you have the proper means for execution, understand the safety risks involved, or preferably, not at all. I also strongly recommend looking up the MSDS for chlorine gas.

 

I am also aware of another means, using mercury, as a reducing agent, to create a mercury sodium amalgam, and then reacting it with water, however, due to production of mercury vapours and the like, this is another method, I strongly advise against.

 

Honestly, it's a lot cheaper to buy it from hardware stores and the like, and a lot less dangerous and time- consuming.

Edited July 23, 2009 by Theophrastus

[Fuzzwood]

Voltage? Nah, its Amperage or current that counts; the number of electrons you pump into the system.

[Theophrastus]

Ah damn, did I really say voltage? Well yeah, true, it's current that counts. For example, electricity, even at a low voltage, implying a high current can still be lethal. Thanks for cleaning that up!

[NATT]

lol Mr.Fswd...

BTW.. I gotta know that NaOH is a strong and a ccorrosive basic... So how can i get Solid NaOH by electrolyzing NaCl solution....

[Fuzzwood]

It's very unsafe, so don't. I know you don't care about safety and will proceed with this stupid experiment anyway, but i'm still stating it. Chlorine gas isn't cool as it burns your lungs away.

 

If you don't even care how redox chemistry works, you really shouldn't be messing with this stuff, and you will only act like a monkey guided by some 2nd rate recipe.

[Melvin]

You could always make it from slaked lime and soda ash:

 

Ca(OH)2 + Na2CO3 --> 2NaOH + CaCO3

[insane_alien]

If you are going to be doing that can you film it and set it to auto-upload to youtube? i want to see an idiot cough up his lungs (literally)

[Theophrastus]

You could always make it from slaked lime and soda ash:

 

Ca(OH)2 + Na2CO3 --> 2NaOH + CaCO3

 

Sorry Melvin, but I believe that you put in the arrow, going the wrong way :

 

[ce] 2NaOH + CaCO3 -> Na2CO3 + Ca(OH)2 [/ce]

[John Cuthber]

Sorry Melvin, but I believe that you put in the arrow, going the wrong way :

 

[ce] 2NaOH + CaCO3 -> Na2CO3 + Ca(OH)2 [/ce]

 

I don't

That's the classic way of making NaOH (and KOH). You need to use fairly dilute solutions to get it to work. It relies on the fact that Ca(OH)2 is a lot more soluble than CaCO3.

[Melvin]

Sorry Melvin, but I believe that you put in the arrow, going the wrong way :

 

[ce] 2NaOH + CaCO3 -> Na2CO3 + Ca(OH)2 [/ce]

 

Ca(OH)2 is not very soluble in water but it is much more soluble than CaCO3, so it does work

 

Believe me, I've done it before

[NATT]

It's very unsafe, so don't. I know you don't care about safety and will proceed with this stupid experiment anyway, but i'm still stating it. Chlorine gas isn't cool as it burns your lungs away.

 

If you don't even care how redox chemistry works, you really shouldn't be messing with this stuff, and you will only act like a monkey guided by some 2nd rate recipe.

 

i jz had experienced th smell of cl2 in my school lab..........oooh damn i was coughing for hours.....and dat damn gas so2........really damnsome...

[thenorthstar12]

Lye really is too cheap to make yourself. Not worth the mess. I just buy mine: http://www.dudadiesel.com/biodiesel_chemicals.php

[Justonium]

the solubility of calcium hydroxide goes up immensely in hot water, so just boiling calcium hydroxide with sodium carbonate will give a good yield of lye even if there is not enough water to dissolve the original lime, because as the lime is consumed more can dissolve. The solubility does go down over time due to the increased number of hydroxide ions but it still remains somewhat high as long as the water is hot. The water must be distilled or de-ionized because tap water contains calcium, which will decrease the solubility of the lime.

[lucky45]

No Its Not. Just go to hardware store and buy a bottle of lye for 4 dollors

[insane_alien]

No Its Not. Just go to hardware store and buy a bottle of lye for 4 dollors

 

which will be chock full of impurities

[John Cuthber]

which will be chock full of impurities

 

Why?

[insane_alien]

because lye bought from the hardware store is rarely purely a sodium hydroxide solution.

[John Cuthber]

The stuff I buy is pretty clean. I guess it depends where you buy the it.

[insane_alien]

probably, but everytime i've used it from a hardware store its been pretty obvious that soemthing else was in it. either the solution turning brown and once even a chlorine smell when the other reactants didn't contain anything like chlorine.

[UC]

probably, but everytime i've used it from a hardware store its been pretty obvious that soemthing else was in it. either the solution turning brown and once even a chlorine smell when the other reactants didn't contain anything like chlorine.

 

That's never been an issue where I am. A few percent of water and a bit of sodium carbonate is to be expected, but otherwise the material is clean if you buy carefully. Most brands have sodium nitrate, aluminum chips, dyes, etc. mixed in. I've been lucky enough to scout out two brands that are nothing but clean white prills, which I mainly use to make soap. If they had significant impurities in them, the oils wouldn't saponify properly and the bars would be greasy and soft. MSDS are always a good place to check before you buy. If the NaOH is caked in the container, it's also a bad idea to buy because a significant amount of water and CO2 has probably made it's way in.

[ajkoer]

OK, I just thought of a possible way (others can comment on the chemistry and perhaps try it). The ingredients are household ammonia and baking soda:

 

NH4OH (in excess) + NaHCO3 = NaOH + NH4HCO3

 

Let solution react at room temperature in a sealed container as heating in an open vessel may cause loss of NH3 thereby driving the reaction to the left in spite of the use of excess NH4OH. Then, cool the solution and try to precipitate out the ammonium hydrogen carbonate. Evaporate the remaining solution to recover NaOH. Heating the solid residue should removing any NH3HCO3 as at fairly low temperature (under 100C), NH4HCO3 breaks down:

 

NH4HCO3 = NH3 + CO2 + H2O

 

leaving just NaOH (?).

 

If high purity is required, one could heat the household ammonia and pass the NH3 into a solution of baking soda dissolved in distilled water.

 

Good luck.

Edited May 3, 2011 by ajkoer