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WHY ΔG'remanins ΔG'. even when temperature is changing —Preceding unsigned comment added by 122.167.19.230 ( talk) 05:46, 15 August 2007 (UTC)
referring to the diagram at [1], the following article text is confusing: "but the ΔG of the oxidation always becomes more negative with higher temperature, and thus the reaction becomes more probable statistically. At a sufficiently high temperature, the sign of ΔG may invert (becoming negative) and the oxide can spontaneously reduce to the metal." -- 99.233.186.4 ( talk) 14:38, 26 December 2009 (UTC)
Does anyone know something about Ellingham and when he/she introduced this diagram? Ideally we should give the original reference.
Also, the French Wikipedia has two relevant articles: one on the Ellingham diagram which is a shortened version of this one, and a second on the "Ellingham approximation" which is said to be that ΔH(T) and ΔS(T) are approximately constant over a wide range of T. This English article does make the equivalent statement that all Ellingham diagrams are basically straight lines, but is this really known as the Ellingham approximation? If someone has a source, it would be interesting to insert the fact in this article (though I think a second article is not necessary). Dirac66 ( talk) 01:18, 16 October 2010 (UTC)
In response to the diagram request posted today, I have inserted a diagram from Commons which I found in the French article. I used (some of) the English caption in the Commons description, but there are still a few French words on the actual diagram which hopefully are simple enough for everyone.
There are also some more elaborate diagrams in the external links, but usually these cannot actually be copied into the article because of copyright problems. Dirac66 ( talk) 17:36, 28 October 2010 (UTC)
It is commonly known that iron/chrome carbides are stable at lower temperatures in the presence of carbon monoxide than are the metals. The statement that chrome carbides are stable at high temperatures and that carbon can therefore not be used to form chrome metal, must be wrong. Could someone please prove me wrong or explain the fact that chrome ore is commonly reduced with carbon. In an article "Solid state reduction of chromite with CO", authors Xiao, Schuffeneger, Reuter, Holappa and Seppala, a photomicrograph is shown with chrome metal and no carbides in the immediate vicinity. — Preceding unsigned comment added by 83.111.212.208 ( talk) 16:12, 28 March 2013 (UTC)
![]() | This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
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WHY ΔG'remanins ΔG'. even when temperature is changing —Preceding unsigned comment added by 122.167.19.230 ( talk) 05:46, 15 August 2007 (UTC)
referring to the diagram at [1], the following article text is confusing: "but the ΔG of the oxidation always becomes more negative with higher temperature, and thus the reaction becomes more probable statistically. At a sufficiently high temperature, the sign of ΔG may invert (becoming negative) and the oxide can spontaneously reduce to the metal." -- 99.233.186.4 ( talk) 14:38, 26 December 2009 (UTC)
Does anyone know something about Ellingham and when he/she introduced this diagram? Ideally we should give the original reference.
Also, the French Wikipedia has two relevant articles: one on the Ellingham diagram which is a shortened version of this one, and a second on the "Ellingham approximation" which is said to be that ΔH(T) and ΔS(T) are approximately constant over a wide range of T. This English article does make the equivalent statement that all Ellingham diagrams are basically straight lines, but is this really known as the Ellingham approximation? If someone has a source, it would be interesting to insert the fact in this article (though I think a second article is not necessary). Dirac66 ( talk) 01:18, 16 October 2010 (UTC)
In response to the diagram request posted today, I have inserted a diagram from Commons which I found in the French article. I used (some of) the English caption in the Commons description, but there are still a few French words on the actual diagram which hopefully are simple enough for everyone.
There are also some more elaborate diagrams in the external links, but usually these cannot actually be copied into the article because of copyright problems. Dirac66 ( talk) 17:36, 28 October 2010 (UTC)
It is commonly known that iron/chrome carbides are stable at lower temperatures in the presence of carbon monoxide than are the metals. The statement that chrome carbides are stable at high temperatures and that carbon can therefore not be used to form chrome metal, must be wrong. Could someone please prove me wrong or explain the fact that chrome ore is commonly reduced with carbon. In an article "Solid state reduction of chromite with CO", authors Xiao, Schuffeneger, Reuter, Holappa and Seppala, a photomicrograph is shown with chrome metal and no carbides in the immediate vicinity. — Preceding unsigned comment added by 83.111.212.208 ( talk) 16:12, 28 March 2013 (UTC)