halogen
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cheap NaOH
2NaHCO3+heat --> H2O+CO2+Na2CO3
Na2CO3+heat --> Na2O + CO2
Na2O + H2O -->2NaOH
But heres the problem (well not really)
Would Na2O react with oxygen in air to form Na2O2?
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
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Esplosivo
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halogen, that's not the problem. You see group I carbonates are highly stable, and do not decompose by heat to give the oxide except lithium
carbonate. Therefore the following reaction cannot occur:
Na2CO3+heat --> Na2O + CO2
The Na2O + H2O --> 2NaOH would occur if you succeded in making Na2O anyway. Na2O2 would simply react with water giving the hydroxide and O2 gas.
Theory guides, experiment decides.
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rikkitikkitavi
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Actually it does occur. T
he problem is that the decomposition rate is slow , even at the melting point of Na2CO3 so the temperature has to be increased even further , and a
melt of Na2O is extremely corrosive towards most materials. (we are talkning 1100-1200 C)
Na2O2 is not stable at this temperatures, so it would not be formed.
Also, NaHCO3 is not very cheap compared to NaOH- but if you have quicklime (CaO) or lime hydrate( Ca(OH)2 ) mixining this solid with NaHCO3 or Na2CO3
solutions preciptate CaCO3 and leaves a NaOH solution (old industrial route )
/rickard
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kazaa81
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Point of view...
Hallo to all,
this probably won't help, but I decided to post.
NaOH seems to me to be cheap itself....if you buy it in hardware store or something similar in your country.
If you buy it at a scientific supplier, depends too on what supplier, it would be less cheap.
NaOH from hardware store that I've buyed is 97-98% pure, this suffice to me but, if you need it very pure for particular analytical experiments,
then a scientific supplier is your only alternative, probably.
Have fun
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