Geoid: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Mhdarin
mNo edit summary
en>Tom.Reding
m Gen fixes (page/s, endash, &nbsp, et al., unicodify, concising wikilinks, etc.), ref cleanup using AWB
 
Line 1: Line 1:
In [[chemistry]], the '''standard molar entropy''' is the [[entropy]] content of one [[mole (unit)|mole]] of substance, under standard conditions (not standard temperature and pressure [[Standard conditions for temperature and pressure|STP]]).


The standard molar entropy is usually given the symbol ''S''°, and as units of [[joule]]s per mole [[kelvin]] (J mol<sup>−1</sup> K<sup>−1</sup>). Unlike [[standard enthalpy change of formation|standard enthalpies of formation]], the value of ''S''° is an absolute.  That is, an element in its standard state has a nonzero value of ''S''° at room temperature. The entropy of a pure [[crystalline]] structure can be 0 J mol<sup>−1</sup> K<sup>−1</sup> only at 0 K, according to the [[third law of thermodynamics]]. However, this presupposes that the material forms a 'perfect [[crystal]]' without any frozen in entropy (defects, dislocations), which is never completely true because crystals always grow at a [[finite]] temperature.  This residual entropy is often quite negligible.


==Thermodynamics==
Most of us know that the development of electrical computers results in the powerful emergence of the Web. Infact, the World Wide Web comes with an important impact on us. With computers linked to network, the options of things we can do is endless. Videos, music, shows, games, information -- it is all on a broad selection of sites worldwide.<br><br>Some individuals might find your product useful and appealing. They might request more appropriate information. Like A responsible marketer, do not forget to reply to such e-mails. Reply within twenty four hours, normally the individual might weary in your item. A delay might be caused by in sending comments Technical problems. In such instances, Reply' and 'Apologize appropriately to the user.<br><br>Your product has enhanced odds of getting viewed and above all understood, whenever your product material is readable. It takes to be created in this way, that all and every individual of one's focused communities understands just what you intend to claim and ultimately promote.<br><br><br><br>Advertising Networks can be a single-point of contact where you've use of a variety of sites to place your ads. In the place of individually seeking these sites out. You're in a position to gain access to many different them about the same circle. Additionally, you are billed using one invoice for almost any choices that you've selected.<br><br>+Time consuming. [https://twitter.com/zeitpop Jordan Kurland] can be very time intensive. Particularly if you do not understand what you are doing. One method to overcome that is to acquire the proper resources to assist you out.<br><br>Always enquire and try to find suggestions, testimonials and case studies. You can actually require the device amount of some of their delighted customers and the email address and speak to them.<br><br>Click here to hear the very FIRST show - "Where to direct all your efforts on-line: Finding A site" Click here to go to the show site to help you see announcement about previous shows and the upcoming shows.<br><br>Deyrolle look is the place where you can buy a stuffed elk, a frog's skeleton and you can also view several creatures of all styles including geese, rabbits, foxes, butterflies and etc.
 
If a [[mole (unit)|mole]] of substance were at 0 K, then warmed by its surroundings to 298 K, its total molar entropy would be the addition of all ''N'' individual contributions:
 
:<math>S^\circ = \sum_{k=1}^N \Delta S_k =\sum_{k=1}^N \int  \frac{dq_k}{T} \, dT</math>
 
Here, ''dq<sub>k</sub>''/''T'' represents a very small exchange of [[heat]] [[energy]] at [[temperature]] ''T''. The total molar entropy is the sum of many small changes in molar entropy, where each small change can be considered a [[Reversible process (thermodynamics)|reversible]] process.
 
==Chemistry==
 
The standard molar entropy of a [[gas]] at [[Standard conditions for temperature and pressure|STP]] includes contributions from:<ref>{{cite book | last = Kosanke| first =  K. | coauthors =  | title = Pyrotechnic chemistry | publisher =  Journal of Pyrotechnics | year = 2004| isbn = 1-889526-15-0 | chapter = Chemical Thermodynamics | page = 29 }}</ref>
 
* The [[heat capacity]] of one mole of the [[solid]] from 0 K to the [[melting point]] (including heat absorbed in any changes between different [[crystal structure]]s)
* The [[latent heat of fusion]] of the solid.
* The heat capacity of the [[liquid]] from the melting point to the [[boiling point]].
* The [[latent heat of vaporization]] of the liquid.
* The heat capacity of the [[gas]] from the boiling point to room [[temperature]].
 
Changes in entropy are associated with [[phase transitions]] and [[chemical reactions]]. [[Chemical equations]] make use of the standard molar entropy of [[reactants]] and [[Product (chemistry)|products]] to find the standard entropy of reaction:<ref>{{cite book | last = Chang| first =  Raymond | coauthors = Brandon Cruickshank | title = Chemistry | publisher =  McGraw-Hill Higher Education | year = 2005 | isbn = 0-07-251264-4 | chapter = Entropy, Free Energy and Equilibrium | page = 765 }}</ref>
 
: Δ''S''°<sub>rxn</sub> = ''S''°<sub>products</sub> – ''S''°<sub>reactants</sub>
 
The standard entropy of reaction helps determine whether the reaction will take place [[spontaneous process|spontaneously]]. According to the [[second law of thermodynamics]], a spontaneous reaction always results in an increase in total entropy of the system and its surroundings:
 
: Δ''S''<sub>total</sub> = Δ''S''<sub>system</sub> + Δ''S''<sub>surroundings</sub> > 0
 
==See also==
*[[Entropy]]
*[[Heat]]
*[[Gibbs free energy]]
*[[Helmholtz free energy]]
*[[Third law of thermodynamics]]
 
==References==
{{reflist}}
 
==External links==
*[http://users.humboldt.edu/rpaselk/C110/C110Notes/C110_lec06.htm Free Energy and Chemical Reactions] - Course notes for General Chemistry (R. Paselk, Humboldt State University)
 
[[Category:Chemical properties]]
[[Category:Thermodynamic entropy]]

Latest revision as of 15:29, 27 December 2014


Most of us know that the development of electrical computers results in the powerful emergence of the Web. Infact, the World Wide Web comes with an important impact on us. With computers linked to network, the options of things we can do is endless. Videos, music, shows, games, information -- it is all on a broad selection of sites worldwide.

Some individuals might find your product useful and appealing. They might request more appropriate information. Like A responsible marketer, do not forget to reply to such e-mails. Reply within twenty four hours, normally the individual might weary in your item. A delay might be caused by in sending comments Technical problems. In such instances, Reply' and 'Apologize appropriately to the user.

Your product has enhanced odds of getting viewed and above all understood, whenever your product material is readable. It takes to be created in this way, that all and every individual of one's focused communities understands just what you intend to claim and ultimately promote.



Advertising Networks can be a single-point of contact where you've use of a variety of sites to place your ads. In the place of individually seeking these sites out. You're in a position to gain access to many different them about the same circle. Additionally, you are billed using one invoice for almost any choices that you've selected.

+Time consuming. Jordan Kurland can be very time intensive. Particularly if you do not understand what you are doing. One method to overcome that is to acquire the proper resources to assist you out.

Always enquire and try to find suggestions, testimonials and case studies. You can actually require the device amount of some of their delighted customers and the email address and speak to them.

Click here to hear the very FIRST show - "Where to direct all your efforts on-line: Finding A site" Click here to go to the show site to help you see announcement about previous shows and the upcoming shows.

Deyrolle look is the place where you can buy a stuffed elk, a frog's skeleton and you can also view several creatures of all styles including geese, rabbits, foxes, butterflies and etc.