Talk:Phosphorus pentoxide
From Wikipedia, the free encyclopedia
 |
Phosphorus pentoxide is within the scope of WikiProject Chemicals, which aims to improve Wikipedia's coverage of chemicals. To participate, help improve this article or visit the project page for details on the project. | ||
 |
This article is also supported by WikiProject Chemistry. | ||
|
Article Grading: The article has not been rated for quality and/or importance yet. Please rate the article and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article.. |
|||
Contents |
[edit] Melting point
how can the compound boil at a lower temperature (in text) than it melts (in window)? —Preceding unsigned comment added by 194.53.253.50 (talk) 14:57, 17 March 2008 (UTC)
Which states is it in at different temeratures? i.e. when is it a solid, liquid and gas?
[edit] Article name
I am concerned about the equation for the reaction of Phosphorus Pentoxide with water. It seems to me that the charg of PO3 should be -3, thus HPO3 is not correct.User:Glander
- It's fine, PO33- is P(III) (see phosphorous acid) and here the discussion is focused on P(V). Also HPO3 is an idealized formula for partial hydrate.--Smokefoot 17:18, 9 October 2006 (UTC)
I feel that phosphorus pentoxide would be a better name for the article than diphosphorus pentoxide. I've heard the former used exclusively to refer to P4O10. Only on WP have I seen diphosphorus pentoxide used (other than in lists of synonyms)! If we're going to use fully systematic names, then we should use tetraphosphorus decoxide. But as far as I'm aware, the standard practice is to name a compound article after the compound's most common name - which in this case is phosphorus pentoxide.
Google search data:
- Phosphorus pentoxide: 209,000 hits
- Diphosphorus pentoxide: 11,000 hits
- Tetraphosphorus decoxide: 596 hits
- Tetraphosphorus decaoxide: 459 hits
This is one piece of evidence that suggests a name change might be in order.
I don't know how to change the name of the article myself, so maybe someone else can do it if there is agreement on a name change.
For the meantime, state your support for or rejection of my proposal here.
Ben 11:22, 1 August 2006 (UTC).
- support for name change to phosphorus pentoxide. I think that all that is needed is "move" it and then check the redirects.
--Smokefoot 04:21, 20 September 2006 (UTC)
-
- SupportPyrotec 18:42, 20 September 2006 (UTC)
Moved as per discussion. --Rifleman 82 17:12, 24 September 2006 (UTC)
[edit] Formula
I was asked to give the formula for diphosphorus pentoxide, and was marked incorrect when I wrote the molecular formula given on this page, leading to much confusion on my part. When writing a balanced equation for the reaction between this compound and water (forming phosphoric acid), which do I use: the molecular formula or the empirical formula? - Guest User
- You could use either:
- P2O5 + 3H2O → 2H3PO4
- or
- P4O10 + 6H2O → 4H3PO4
- I hope this answers your question.
- Ben 10:34, 10 February 2007 (UTC)
[edit] Calculation of Hydration Energy
I could not find a direct source for hydration energy, so the number I entered into the article is calculated. The table below documents the calculation. Heats of formation, ΔHf, at 25°C data are taken from Lange's 10th ed.
-
compound and state ΔHf P4O10 (amorphous) –734.0 kCal H2O (liquid) –68.32 kCal 2H2O (liquid) –136.64 kCal P4O10 (am) + 2H2O (lq) –870.64 kCal HPO3 (crystal) –228.2 kCal 4HPO3 (crystal) –912.8 kCal net ΔH –42.24 kCal convert to kJ and round to nearest unit –177 kJ
In expressing the format and sign of this ΔH in the equation, I used the convention that was used in sulfur trioxide, even though I disagree with it (convention has heat given up by a reaction as negative). So if you change the sign in this equation, please do so also on sulfur trioxide. Karlhahn 12:42, 24 September 2006 (UTC)
