Talk:Sodium carbonate
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[edit] crystal form wrong?
I think that it's crystal form is wrong! in my chemestry kit it say that Sodium Carbonate is is Rhombic crystals.
I belive, that your chemistry kit is not referring to sodium carbonate, but rather to sodium carbonate monohydrate (orthorhombic / needles)or decahydrate (monoclinic-domatic / hexagonal platelets) crystals. It is tricky, to produce crystals of water-free sodium carbonate, because from aqueous solution, only the hydrated forms crystallize. Water-free sodium carbonate crystallizes as hexagonal platelets. The soda ash you get commercially is produced by dehydrating (calcining) the monohydrate or the bicarbonate. So it is composed of agglomerates of micron-sized crystals. Mirkano (talk) 12:31, 25 April 2008 (UTC)
[edit] Uses
stating uses for it would be helpful. like making tyedye shirts.
It is also use as an acidity regulator; but that's all I know. KILO-LIMA 13:58, 26 February 2006 (UTC)
Soda ash is commonly used to raise the Ph in swimming pools and spas.
I think the staments in the artical concerning the usaes of Sodium Carbonate in photography are misleading and inaccurate. The primary use of Sodium carbonate in photography is in B&W film developers. It is (or was) commonly used as the alkali which is necessary to activate the developing agent.
[edit] Reactions
I'd like to ask: If it were heated, would it not transform to to carbon dioxide and sodium oxide?
Thats what i would have thought, but when i heated Sodium Bicarbonate until it decomposed into sodium carbonate then treated it with 12 molar HCl giving me something that ressembled Calcium Sulfate (plaster of paris). Any thoughts??
Heat sodium bicarbonate until it decomposes fully into sodium carbonate. Then heat it some more, see if it decomposes. THEN, if it does, put it in a solution of baker's ammonia ((NH4)2CO3). If this makes it reek of ammonia, then you have put something basic in it, which would indicate that you put Na2O in it. I'd try it myself, but I have improper heating devices.
[edit] Answers to reactions
Sodium bicarbonate decomposes to sodium carbonate, water and carbon dioxide on heating. It does not decompose any further under normal heating. Sodium bicarbonate is a weak base, sodium carbonate is a strongish base and will liberate ammonia from its salts.
Sodium oxide would react very exothermically with water to form sodium hydroxide.
Treating sodium carbonate with hydrochloric acid would produce a paste of sodium chloride if the concentrations were high enough. It has nothing to do with calcium sulfate.
Socksysquirrel 17:08, 27 April 2007 (UTC)
Plus you can smell already 50ppm of ammonia (NH3) - with 1000ppm overloading your nose with sensory input, so you might not smell much else anymore for a while. So checking for ammonia smell is not a good indicator and can be quite uncomfortable. —Preceding unsigned comment added by Mirkano (talk • contribs) 10:17, 21 March 2008 (UTC)
[edit] Also used for dyeing fabrics
Would any of you chemists be able to include some of this info on this page? http://www.pburch.net/dyeing/FAQ/sodaash.shtml
[edit] Molecular diagram missing carbon
The molecule diagram shows three oxygen atoms, two sodium -- where's the carbon? (I understand where it is, but given the formula "Na2CO3" wouldn't it be better to have an explicit "C" in there?) — Johan the Ghost seance 09:34, 30 August 2006 (UTC) / 12:59, 30 August 2006 (UTC)
Chemists typically leave the "C" for carbon out of molecular diagrams, assuming that anyone who is bothering to look at these knows that when four bonds converge, and the atom isn't specifically stated, it's a carbon. Also, if you see one with less than four bonds, you can assume that enough hydrogens are on it to bring each carbon up to four bonds; just look at the diagram for butane. Cgirten 18:45, 10 February 2007 (UTC)
I am not a chemist, I did look at the diagram. My initial reaction was "shouldn't there be a carbon atom between those oxygen atoms?" I even added a new discussion topic about it until I noticed this one. I think it might be useful to put it in there even if it should be assumed. It's a simple enough structure that a non-chemist like myself might want to look at it. - Tekemperor 23:59, 17 October 2007 (UTC)
[edit] Relationship to Leblanc process and Solvay process articles
I feel that the "Production" section of this article should be adapted to recognize the present state of the articles on the Leblanc process and the Solvay process. I'm thinking that the detailed descriptions of these processes should be curtailed in the present article, with more emphasis on the pros and cons of each process. In addition, this section should comment on the production method from which the name "soda ash" was derived: from the ashes of marine plants (barilla & kelp). The Kiefer article mentions that 100,000 Scotsmen were involved in this activity in 1700s!
Any comments?EAS 09:24, 21 October 2006 (UTC)
[edit] MSDS
The MSDS link is broken, can someone add the correct one? dq 14:10, 30 May 2007 (UTC)
[edit] Decomposes to Sodium Oxide at what temperature?
This compound melts at 851 °C. But the boiling point only says decomposes. what is that decomposition temperature? It should be there. 97.82.247.200 23:45, 26 July 2007 (UTC)
[edit] Please confirm ´Hou´s Process´
As a chemical engineer, having worked for years in research on the production of sodium carbonate, I have never heard of Hou´s process nor of a process scheme as outlined in the section. As the description is quite brief, the explanations might be overly simplified, misleading or partially incorrect. From the given description, the process does not make sense: It is stated, that Hou´s process avoids the use of lime and the calcination of lime stone. As the section on the Solvay process illustrates, is the limestone (CaCO3) serving as a source of carbon dioxide (CO2) and alkaline (OH- from Ca(OH)2 via CaO). In Hou´s process, no source of CO2 is given, but it is apparently used in even larger amounts than in the Solvay process. As CO2 could also be recovered (with a lesser chemical purity) from flue gases (exhaust gases of waste incinerators, power stations, etc.), this is not a major issue. A major issue is, that no process to recover the ammonia (NH3) from the NH4Cl is proposed. Furthermore, it is stated that NH4Cl is extracted from the process by (cooling) crystallization (which is not quantitative, as ca. 50% of the NH4Cl will remain in solution even at 0°C and ca. 70% at 10°C). Obviously, ammonia has to be recycled in the process, to make it work economically. And for this, it has to be added in the form of NH3 or NH4OH back into the process. As Hou´s process, stated to be ´the current main process to produce sodium carbonate´ is neither well-known nor industrially functioning, I would propose to delete the section on Hou´s process, if it cannot be verified by literature references or by other reliable sources.
- Google finds citation's to Hou's process on Chinese chemical company websites. There are also mentions of Ammonium Chloride coproduction, which might be the same thing, and to some other processes (New Asahi Process, ...)
- When Hou's process was added a paragraph giving the Solvay process and mining as the main sources was removed. Perhaps that should be reinstated. Lavateraguy (talk) 11:30, 21 March 2008 (UTC)
Thank you. I did some check up with your keywords - and it fits indeed. But this will be a difficult issue to settle here. I am afraid, there is some chinese-japanese sensibilities involved. Anyhow, Hou´s process[1] - apparently indeed identical to the (ammonium chloride) coproduction process - appears to be the same as a variant of the New Asahi process - which in turn is a variant of the original Solvay process. Difference between the Solvay and the New Asahi is just the method of contacting the sodium chloride with the caustic ammonia solution (with the New Asahi being nominally more efficient) and the option to extract ammonium chloride as a salt for fertilizer production. This of course requires the ammonia to be continuously replaced, so they require an ammonia plant (e.g. Haber-Bosch process) on site. This is quite expensive compared to simple lime burning of the Solvay process - and you need an alternative source of CO2, otherwise you have to sell some amount of quicklime (CaO) in addition to your fertilizer, but if you have no market outlet for CaCl2 and a good fertilizer market, it is an attractive alternative. Regarding to the Hou / New Asahi name of the process, depends apparently on whether you asked a chinese person or ...mhm... somebody else. The chinese claim, the process was invented by Hou Debang between 1930 and 1941. Of course during this time, the japanse invaded China (1937) - and occupied also the plant, where Mr. Hou was developing his process. You might fill in the rest of the story... Suffice to say, it is obscure, who did the invention - especially since it is essentially only a variation of the Solvay process. So you find no big claims from japanese corporations, but they used & use this process extensively for soda production. And since the process was most widely applied by Asahi Glass[2] (who reputedly invented it as well), it has become known as the New Asahi process. And under this name, it can be found in literature. So changing the entry would be logical, but might become a political issue.
And I agree strongly with you. The trona mining and processing has to go back in: In the US, mining is the main source of soda ash. In Europe, it is the Solvay process with some modifications. And in China/Japan/Asia? the New Asahi / Hou process is the main route - as they use~(d) this type of fertilizer for rice paddies. Mirkano (talk) 12:50, 4 April 2008 (UTC)
