Talk:Phosphorous acid

message: Is the phosphite H of phosphorous acid not ionisable? the corresponding H in the corresponding esters (such as diethyl phosphite) can be easily removed with bases such as NaH, in a preparatively useful manner. it isn't too much of a stretch to think the same applies to phosphorous acid. Xcomradex 22:57, 25 June 2006 (UTC)
replies: text: My two-cents worth - the hazard/flaw in this style of thinking is that HP(O)(OEt)2 is charge-neutral whereas [HPO3]2- is a dianion.  Charge strongly affects pKa.  Using your logic, the acidity of MeOH would anticipate that OH- is ionizable, i.e. that O2- would be stable in soln.  It is plausible that the proton in [HPO3]2- is ionizable, but the existence of Na3[PO3] does not prove this.  For one thing, what would this stuff be soluble in?   Na2O and  Na3P are also known, but they have no solution chemistry.--Smokefoot 00:48, 26 June 2006 (UTC)

text: Xcomradex: amazing and nifty chemical factoid. Like you say, if NaOH can be used, then something is deprotonatable.Thanks for taking the time to comment. Best wishes,--Smokefoot 23:47, 28 June 2006 (UTC)

message: The image is IMHO misleading. The dimensions are those found in the solid which is extensivelly H bonded--Axiosaurus (talk) 12:15, 24 March 2008 (UTC)
replies: text: Also conflict between picture (which takes dimensions from this paper  and the article which uses Wiberg. Does anyone know where Wiberg took its data from?--Axiosaurus (talk) 09:42, 25 March 2008 (UTC)
thread_title:  image-bond lengths etc actually relates to the solid form 

message: In the phosphonic acid article (unreferenced) it mentions the two tautomeric forms one, [P(OH)3] named phosphorous acid and the other, [PHO(OH)2], phosphonic. Is there a ref for the equilibrium? Wiber g just says lies entirely to the right i.e (HPO(OH)2.Re name is there a right answer or are, in the confusing world of P acid naming, both sort of right? --Axiosaurus (talk) 12:23, 24 March 2008 (UTC)
thread_title:  The [[phosphonic acid]] article 

message: if you take 1 mol of H3PO3 and add 3 mol of NaOH you get 1 mol of Na3PO3 plus some water
simple as that  —Preceding unsigned comment added by 70.180.238.179 (talk) 22:33, 7 January 2011 (UTC)
thread_title:  Lede crap 

message: Are you sure the first pka for phosphorous acid is 1.3? I have found many times a pka for phosphorous acid of 2.0. and in the french Wikipedia version, the specified pka is 2.0. I think the true pka is 2.0, as I use phosphorous acid and I measured pH of H3PO3 solutions, it looks close to a pH of 2. Any comments?? Thanks in advance
Tom  — Preceding unsigned comment added by 193.8.28.49 (talk) 07:42, 15 February 2016 (UTC)
replies: text: Thank you for leaving a note.  According to Greenwood and Earnshaw refer to a report that describes these pKa's at RT:
*H3PO4: 2.146
*H3PO3: 1.257
*H3PO2: 1.244
(John W. Larson, Margaret Pippin "Thermodynamics of ionization of hypophosphorous and phosphorous acids. Substituent effects on second row oxy acids" Polyhedron 1989, volume 8, pages 527–530. doi:10.1016/S0277-5387(00)80751-2).  I always assumed that phosphoric was the strongest acid.--Smokefoot (talk) 19:19, 15 February 2016 (UTC)
thread_title:  First pka 

message: To quote from Greenwood and Earnshaw: "Phosphorous acid and phosphites [HPO(OH)2 and HPO32-]: Again, the recommended names (phosphonic acid and phosphonates) have found more general acceptance for organic derivatives such as RPO32-..."  So the parent acid is ordinarily called phosphorous acid.--Smokefoot (talk) 12:17, 16 March 2019 (UTC)
thread_title: Nomenclature