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[[Image:Walther Nernst.jpg|thumb|right|130px|Walther Nernst]]
This is a preview for the new '''MathML rendering mode''' (with SVG fallback), which is availble in production for registered users.


The '''Nernst heat theorem''' was formulated by [[Walther Nernst]] early in the twentieth century and was used in the development of the [[third law of thermodynamics]].
If you would like use the '''MathML''' rendering mode, you need a wikipedia user account that can be registered here [[https://en.wikipedia.org/wiki/Special:UserLogin/signup]]
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== The theorem ==
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The Nernst heat theorem says that as absolute zero is approached, the entropy change ΔS for a chemical or physical transformation approaches 0.  This can be expressed mathematically as follow
'''MathML'''
:<math forcemathmode="mathml">E=mc^2</math>


:<math> \lim_{T \to 0} \Delta S = 0 </math>
<!--'''PNG'''  (currently default in production)
:<math forcemathmode="png">E=mc^2</math>


<br>The above equation is a modern statement of the theorem.  Nernst often used a form that avoided the concept of entropy.<ref>{{cite book | last = Nernst | first = Walther | title = The New Heat Theorem | publisher = Methuen and Company, Ltd | year = 1926 | pages = }}- Reprinted in 1969 by Dover - See especially pages 78 &ndash; 85</ref>
'''source'''
:<math forcemathmode="source">E=mc^2</math> -->


[[Image:Nernst Walter graph.jpg|right|thumb|Graph of energies at low temperatures]]
<span style="color: red">Follow this [https://en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-rendering link] to change your Math rendering settings.</span> You can also add a [https://en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-rendering-skin Custom CSS] to force the MathML/SVG rendering or select different font families. See [https://www.mediawiki.org/wiki/Extension:Math#CSS_for_the_MathML_with_SVG_fallback_mode these examples].


Another way of looking at the theorem is to start with the definition of the Gibbs free energy (G), G = H - TS, where H stands for enthalpy.  For a change from reactants to products at constant temperature and pressure the equation becomes <math>\Delta G = \Delta H - T\Delta S</math>.
==Demos==


In the limit of T = 0 the equation reduces to just ΔG = ΔH, as illustrated in the figure shown here, which is supported by experimental data.<ref>{{cite book | last = Nernst | first = Walther | title = Experimental and Theoretical Applications of Thermodynamics to Chemistry | publisher = Charles Scribner's Sons | year = 1907 |location = New York | pages = 46| url = http://books.google.com/books?id=sYsJAAAAIAAJ&printsec=frontcover&dq=Walther+nernst}}- The labels on the figure have been modified.  The original labels were A and Q, instead of ΔG and ΔH, respectively.</ref> However, it is known from [[Gibbs–Helmholtz equation|thermodynamics]] that the slope of the ΔG curve is -ΔS.  Since the slope shown here reaches the horizontal limit of 0 as T → 0 then the implication is that ΔS → 0, which is the Nernst heat theorem.
Here are some [https://commons.wikimedia.org/w/index.php?title=Special:ListFiles/Frederic.wang demos]:


The significance of the Nernst heat theorem is that it was later used by [[Max Planck]] to give the [[third law of thermodynamics]], which is that the entropy of all pure, perfectly crystalline homogeneous materials is 0 at [[absolute zero]].


== See also ==
* accessibility:
** Safari + VoiceOver: [https://commons.wikimedia.org/wiki/File:VoiceOver-Mac-Safari.ogv video only], [[File:Voiceover-mathml-example-1.wav|thumb|Voiceover-mathml-example-1]], [[File:Voiceover-mathml-example-2.wav|thumb|Voiceover-mathml-example-2]], [[File:Voiceover-mathml-example-3.wav|thumb|Voiceover-mathml-example-3]], [[File:Voiceover-mathml-example-4.wav|thumb|Voiceover-mathml-example-4]], [[File:Voiceover-mathml-example-5.wav|thumb|Voiceover-mathml-example-5]], [[File:Voiceover-mathml-example-6.wav|thumb|Voiceover-mathml-example-6]], [[File:Voiceover-mathml-example-7.wav|thumb|Voiceover-mathml-example-7]]
** [https://commons.wikimedia.org/wiki/File:MathPlayer-Audio-Windows7-InternetExplorer.ogg Internet Explorer + MathPlayer (audio)]
** [https://commons.wikimedia.org/wiki/File:MathPlayer-SynchronizedHighlighting-WIndows7-InternetExplorer.png Internet Explorer + MathPlayer (synchronized highlighting)]
** [https://commons.wikimedia.org/wiki/File:MathPlayer-Braille-Windows7-InternetExplorer.png Internet Explorer + MathPlayer (braille)]
** NVDA+MathPlayer: [[File:Nvda-mathml-example-1.wav|thumb|Nvda-mathml-example-1]], [[File:Nvda-mathml-example-2.wav|thumb|Nvda-mathml-example-2]], [[File:Nvda-mathml-example-3.wav|thumb|Nvda-mathml-example-3]], [[File:Nvda-mathml-example-4.wav|thumb|Nvda-mathml-example-4]], [[File:Nvda-mathml-example-5.wav|thumb|Nvda-mathml-example-5]], [[File:Nvda-mathml-example-6.wav|thumb|Nvda-mathml-example-6]], [[File:Nvda-mathml-example-7.wav|thumb|Nvda-mathml-example-7]].
** Orca: There is ongoing work, but no support at all at the moment [[File:Orca-mathml-example-1.wav|thumb|Orca-mathml-example-1]], [[File:Orca-mathml-example-2.wav|thumb|Orca-mathml-example-2]], [[File:Orca-mathml-example-3.wav|thumb|Orca-mathml-example-3]], [[File:Orca-mathml-example-4.wav|thumb|Orca-mathml-example-4]], [[File:Orca-mathml-example-5.wav|thumb|Orca-mathml-example-5]], [[File:Orca-mathml-example-6.wav|thumb|Orca-mathml-example-6]], [[File:Orca-mathml-example-7.wav|thumb|Orca-mathml-example-7]].
** From our testing, ChromeVox and JAWS are not able to read the formulas generated by the MathML mode.


* [[Theodore William Richards]]
==Test pages ==
* [[Entropy]]


== References and notes ==
To test the '''MathML''', '''PNG''', and '''source''' rendering modes, please go to one of the following test pages:
*[[Displaystyle]]
*[[MathAxisAlignment]]
*[[Styling]]
*[[Linebreaking]]
*[[Unique Ids]]
*[[Help:Formula]]


<references />
*[[Inputtypes|Inputtypes (private Wikis only)]]
 
*[[Url2Image|Url2Image (private Wikis only)]]
== Further reading ==
==Bug reporting==
 
If you find any bugs, please report them at [https://bugzilla.wikimedia.org/enter_bug.cgi?product=MediaWiki%20extensions&component=Math&version=master&short_desc=Math-preview%20rendering%20problem Bugzilla], or write an email to math_bugs (at) ckurs (dot) de .
* {{cite book | last = Denbigh | first = Kenneth | title = The Principles of Chemical Equilibrium | publisher = Cambridge University Press | edition = 3 | year = 1971 }}- See especially pages 421 &ndash; 424
 
== External links ==
* [http://www.nernst.de/#theorem Nernst heat theorem]
 
[[Category:Thermochemistry]]
 
[[de:Nernst-Theorem]]

Latest revision as of 22:52, 15 September 2019

This is a preview for the new MathML rendering mode (with SVG fallback), which is availble in production for registered users.

If you would like use the MathML rendering mode, you need a wikipedia user account that can be registered here [[1]]

  • Only registered users will be able to execute this rendering mode.
  • Note: you need not enter a email address (nor any other private information). Please do not use a password that you use elsewhere.

Registered users will be able to choose between the following three rendering modes:

MathML

E=mc2


Follow this link to change your Math rendering settings. You can also add a Custom CSS to force the MathML/SVG rendering or select different font families. See these examples.

Demos

Here are some demos:


Test pages

To test the MathML, PNG, and source rendering modes, please go to one of the following test pages:

Bug reporting

If you find any bugs, please report them at Bugzilla, or write an email to math_bugs (at) ckurs (dot) de .

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