Talk:Phosphorus pentoxide

message: In the Hazards section of the article, it mentions that P4O10 reacts violently with water.  It doesn't mention what reaction takes place and what the end products are; it only mentions that it is an exothermic reaction.  What is the balanced chemical reaction and its products, and should we include it in the article? Kyoobur9000 (talk) 21:21, 11 October 2012 (UTC)
thread_title: So It Reacts With Water...

message: 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)
thread_title: Melting point

message: 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)
replies: text: 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)
replies: text:  SupportPyrotec 18:42, 20 September 2006 (UTC)
thread_title: Article name

message: 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)
replies: text: The article discusses this in the structure section. The compound exists in multiple forms, all of which have the empirical formula P2O5. One of these forms is molecular and has the molecular formula P4O10. The other forms are not molecular but extend effectively infinitely in one or more dimensions so could be described as (P2O5)∞. --Ben (talk) 19:39, 31 May 2021 (UTC)
thread_title: Formula

message: You accidentally flipped the order of the elements from P_4O_10 to O_10P_4 - in the Molecular formula field.  —Preceding unsigned comment added by 128.205.48.3 (talk) 02:49, 25 January 2009 (UTC)
thread_title: Error in Properties (right side of the page under the art)

message: 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</sub> (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)
thread_title: Calculation of Hydration Energy

message: You accidentally flipped the order of the elements from P_4O_10 to O_10P_4 - in the Molecular formula field.  —Preceding unsigned comment added by 128.205.48.3 (talk) 02:47, 25 January 2009 (UTC)
thread_title: Error in Properties (right side of the page under the art)

message: Many reactions of P2O5 are missing: with carbon, basic oxides (like CaO), hydrogen peroxide oxygen, ammonia. Can someone add them? --Siddhant (talk) 16:47, 7 September 2009 (UTC)
replies: text: That is why it is rated as a C-class article and not a B-class (or GA). Pyrotec (talk) 19:22, 7 September 2009 (UTC)
thread_title:  More reactions needed 

message: 'formula of P2O5' is ambiguous since it is empirical formula not just formula. I have changed it to a molecular formula so that the reader can grasp the concept more easily  —Preceding unsigned comment added by 121.79.5.39 (talk) 06:36, 30 October 2009 (UTC)
thread_title:  Changed to molecular formula 

message: Can we get a photo of the actual chemical? Badagnani (talk) 05:40, 28 November 2009 (UTC)
replies: text: Why? Its just a white powder that forms a glassy surface on exposure to moisture. Pyrotec (talk) 11:54, 29 November 2009 (UTC)

text: Please do. Materialscientist (talk) 05:58, 29 September 2010 (UTC)
thread_title:  Photo 

message: Density about 3,05 g/cm3 and mp 580 C (about 853 K) and polymeric structure of oxide of pentavalent element are not so nonmetallic properties of phosphorus. Are polymeric forms of this oxide stable at STP? If yes, P behaves here as a metalloid!  — Preceding unsigned comment added by 194.29.130.244 (talk) 15:59, 26 November 2013 (UTC)
thread_title:  Not so nonmetallic property of phosphorus? 

message: Strangely this familiar chemical had no importance assigned. It receives a fair number of hits - as many as some high importance chemicals. Axiosaurus (talk) 11:58, 13 January 2014 (UTC)
thread_title: Rated