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Also known as Mofoic acid —Preceding unsigned comment added by 146.6.80.58 ( talk) 23:20, 14 October 2007 (UTC)
Other interesting information could be: Phosphoric acid producers, such as Thermphos International B.V. (www.thermphos.com)
And about Phosphate esters, these are not made from H3PO4 but from P2O5 (Phosphorus pentoxide), PPA (Polyphosphoric acid: highly concentrated phosphoric acid) or POCl3 (Phosphorus oxychloride). I wouldn't mention them here.
Else: there are several ways to produce phosphoric acid, from Wet acid (green acid) that is obtained through the sulphur process described here, but also through a Thermal process, that produces very pure phosphoric acid through the reaction of Water with elemental phosphorus (Yellow phosphorus).
- MahRain. 14 november 2005.
IMHO this article is a real mess:
1. It barely touches on the actual subject of phosphoric acids (of which there are an infinite number in a very rich structural system, but 3 important ones, ortho-, meta- and pyro-);
2. Yet it lurches off to discuss irrelevancies like eutrophication from phosphate detergents (this isn't the phosphate article!) while missing all but one or two of the many uses for this important material;
3. It introduces a lot of dubious material which will need fact checking (local anaesthetic?! colour me very skeptical);
4. It is totally disorganised (section "Chemical properties" contains no chemical properties, section "Preparation of phosphoric acid" contains 11 words on one method of preparation while the whole rest of the section is totally unrelated, etc). I suggest hydrochloric acid might make a good template;
5. The section "Processed food use" is at best POV (agro-industrial chemical ?!? They don't use fertiliser grade acid in colas!) and probably just wrong (citric acid ... obtainable from lemons and limes--sorry, nope, it's an agro-industrial chemical made by the Aspergillus niger mould fermenting scrap molasses and waste starch hydrolysates, and it works best if you add some ... phosphoric acid!);
6. The section "Effects on bone calcium" seems very suspicious. In particular, the claim When an excess of phosphorus (through phosphoric acid, for example) is introduced, the body's chemical balance mechanisms will attempt to maintain the proper calcium-phosphorus ionic ratio by extracting calcium from the bones is exactly the opposite of what would be expected from Le Chatelier's principle and not what is expected for normal homeostasis, but hey, biology is a funny thing, if someone comes up with a reputable cite I'll believe it. If not, I'll remove it. I'm foreshadowing all this here because I have a really long backlog and it might be a while before I get to it. Anyone else, please jump in first if you can. -- Securiger 11:21, 28 Mar 2005 (UTC)
I just deleted the detergent stuff. Phosphoric acid is not phosphate and it is not used in detergent.
The edits made by 152,163.100.66 on June 24, 2006 were actually made by me, H Padleckas. It appeared to me as if I was logged on, which is how I usually make my edits, but somehow only the IP address is listed in the contributions history. 152.163.100.130 14:46, 24 June 2006 (UTC) H Padleckas 15:10, 24 June 2006 (UTC)
A very old rust stripping method uses zinc and sulphuric acid. The steel part is immersed in water in contact with a piece of scrap zinc casting. A little battery acid is added. Add acid until after a few minutes bubbles can be seen coming off the steel. Leave the work in the solution until rust removal is seen to be complete. Remove and wash. Protect from re-rusting immediately, as the steel will be in a very rustable condition. Also remove and wash the zinc for later use or the remaining acid will simply corrode it away to nothing. Pays to mechanically remove flaking rust first or you will simply be using up chemical and zinc for no good reason. This method works very well for pieces of all sizes but it does pay not to load the solution with lots of bits as it seems to slow down rust removal quite substantially, possibly because it is not easy to ensure good electrical contact between lots of bits and the zinc. Use of a steel sieve is really helpful for stripping small parts as this acts as a good contact. Happy stripping. Evan. —Preceding unsigned comment added by 125.237.171.82 ( talk) 07:57, 8 June 2008 (UTC)
The article currently claims that phosphoric acid is used as an anesthetic. Can anyone confirm or deny this?
Darrien 08:42, 2005 May 14 (UTC)
I am an assistant professor of anesthesia at a Canadian teaching hospital. I have never heard of phosphoric acid used as a local anesthetic. Gresch, May 2, 2006, 17:40 UTC
Is he sure he didn't mix up "cyclopropane" with "orthophosphoric"? 68.231.189.108 ( talk) 01:08, 30 October 2009 (UTC)
5. i have just finished reading a book about phosphorus and its compounds. from what i've read so far, calcium deficiency is not the main cause for the bone degeneration, but lack of phosphates.
Was that one of the above editors, accidentally logged out by timeout? The wiki syntax was messed up so I reverted, so I don't think it was a regular editor. - Leonard G. 05:34, 8 September 2005 (UTC)
This imho reliable source http://physchem.ox.ac.uk/MSDS/PH/phosphoric_acid.html gives a different melting point for phosforic acid (21C instead of 42C).
Acros, a big supplier of fine chemicals, also lists 21C on their website.
The same sources give also a different density (1.68 in stead of 1.9) and boiling point (158C vs 213)
From what I understand the dispute seems to be over the effect of phosphoric acid on osteoporosis. The article cites few or no sources, so I'd like to add the following:
But I am unfamiliar with citing practices for non-website sources. —Preceding unsigned comment added by Tzenes ( talk • contribs) 14:34, 12 April 2006
One weak study involving only 30 women studied for the duration of a week does not trump all of those studies, even if it is mischaracterized as "a bunch of studies"
Why is phosphoric acid used in soft drinks?
Norm
It's cheap, non-toxic, highly water-soluble, not too strongly acidic, and gives the kind of sour taste some people probably like. Citric acid, which has some similar properties, is also used in some soft drinks. H Padleckas 20:21, 25 June 2006 (UTC)
This article's got some poor wording. "the skeletal effects of carbonated soft drink consumption are likely due primarily to milk displacement."? Uh...Garbage. Even if the study *citing* it say s it, it's garbage. "Milk" is not necessarily a dietary staple.
Come to think, I'm a bit shocked we're even talking about studies by Pepsi. They're obviously in conflict of interest to the point of being unreliable. 216.14.79.3 ( talk) 19:12, 12 August 2009 (UTC)Ubiquitousnewt
Quoting from the section "Biological effects on bone calcium and kidney health": "On the other hand, another study suggests that insufficient intake of phosphorus leads to lower bone density. The study does not examine the effect of phosphoric acid, which binds with magnesium and calcium in the digestive tract to form salts that are not absorbed, but rather studies general phosphorus intake.[4]". The rest of the articles focus on urinary products rather than digestive products. Would testing urine alone show a measurable precipitation of magnesium or calcium and phosphate salts if it happened somewhere in the digestive system? I thought you would require testing of more solid excretia. Is it possible the section could be summarized in one or two sentences and the rest thrown in discussion or put under more pertinent wikipedia article? There only seems to be one mention of relation to kidney health in the four paragraphs dedicated to "Biological effects on bone calcium and kidney health" and that was of calciuria. Is that to imply that if calcium is excreted via the urinary tract that you are more likely to get Kidney stones? If so, why not cite an article that says it rather than implying it. The lay reader, i.e., me, sees Kidney in the subtitle and expects to see a reference to kidney in the text indicating which part is pertinent to kidney health. Normally, debatable or unproven research results would not be included in an encyclopedia. If you have to imply it, then you probably have insufficient proof, ergo, not encyclopedic. I am not a chemist, biochemist or health professional so I will leave the editing to those with more qualification for editing. Added by Danny Robinson, New Zealand — Preceding unsigned comment added by 119.224.98.136 ( talk) 00:23, 20 February 2012 (UTC)
The following suggestions were generated by a semi-automatic javascript program, and may or may not be accurate for the article in question.
You may wish to browse through User:AndyZ/Suggestions (and the javascript checklist; see the last paragraph in the lead) for further ideas. Thanks, Wim van Dorst ( Talk) 21:10, 26 June 2006 (UTC)
In the final paragraph, this subsection discusses the dehydration of phosphoric acid. That phosphoric acid can be dehydrated by heating to metaphosphoric acid is supported by numerous references that I have found (though there is no mention in the article of the intermediate form of pyrophosphoric acid, which nearly every reference does mention). But the paragraph goes on to say that further dehydration leads to phosphoric anhydride (P4H10). This is, in a sense, true, since chemical dehydration of metaphosphoric acid will lead to this, but in the context of this sentence, it suggests that further heating would cause further dehydration. I can find no reference to support that -- indeed Merck 9th ed. says that metaphosphoric acid volatilizes at red heat. Hence it would be well nigh impossible to dehydrate metaphosphoric acid by heating. Karlhahn 14:21, 23 September 2006 (UTC)
What you are looking for might be difficult to find. I recommend deleting the paragraph that you suspect is misleading and re-writing it based on the facts known to you.-- Smokefoot 15:01, 23 September 2006 (UTC)
You can get futher dehydration of some of the acid salts of phosphoric acid by heating: this is used to make superphosphate fertilizers. From vague memory, I think that metaphosphic acid is the limit for dehydration of the free acid, but, even disregarding the vagueries of my memory, the experimenters may well have missed higher acids (I bet no-one has looked at the question for several decades). I would look and see what you can find on superphosphates, that may give an idea of what happens to the free acid. Physchim62 (talk) 13:21, 25 September 2006 (UTC)
Will elèctròlusis work? -lysdexia 14:05, 10 October 2007 (UTC)
Whoever thought this supported their claim was very wrong.
Here is the reaction of Phosphoric Acid with Calcium:
2 H3PO4 + 3 Ca(OH)2 -> 6 H(OH) + Ca3(PO4)2
According to Le Chatelier's principle, if you add more H3PO4, it pushes the reaction to the right which consumes more calcium.
According to Le Chatelier's principle, if this reaction consumes unbound calcium in the digestive tract, more will be freed from the bone.
The above assumes that bone is in equilibrium with the digestive tract, which is far from the case... It also assumes only two species, also incorrect. Physchim62 (talk) 10:32, 15 January 2007 (UTC)
This article seems to hold a bias in support of Tucker et al. I would recommend presenting Tucker as a counter study to Elmstål, removing the exhaustive discussion of Tucker (from "This is Tucker..." to "...needed to confirm the findings." and leaving it as a reference as is done for the other studies. This discussion is redundant to the citation and biases the article toward this study by presenting it is a more dignified manner. "This is Tucker..." is akward syntactically. mDonaldson 03:56, 15 January 2007 (UTC)
What do you think about this image? Should it be added to "Preparation.." section? Abelin C A usesobad 07:17, 17 January 2007 (UTC)
My mom wants to replenish an old bottle of Dent-U-Care denture cleaner.
It states on bottle "WARNING" "contains phosphoric acid" as the only listed ingredient.
My search produced 2 red flags:
any input on this appreciated
-- Mamatops 22:30, 13 September 2007 (UTC)
Is Image:Luc Viatour phosphore poudre.jpg a picture of phosphoric acid? Calliopejen1 21:27, 15 September 2007 (UTC)
Why it is called orthophosphoric acid instead of phosphoric acid? Can anyone give me th answare? Thanks
Is this really even appropriate for this article?
I mean, a mention of possible health effects is alright, but is this long (dubiously researched) passage on whether or not your bones will melt if you drink soda necessary? Jgr2 ( talk) 16:28, 25 March 2008 (UTC)
I'd say it's valid. That's the reason I looked this article up. The alternative would be for this article to have a link to a separate article that talks about that. 71.92.101.14 ( talk) 05:12, 28 October 2009 (UTC)
This article talk page was automatically added with {{ WikiProject Food and drink}} banner as it falls under Category:Food or one of its subcategories. If you find this addition an error, Kindly undo the changes and update the inappropriate categories if needed. The bot was instructed to tagg these articles upon consenus from WikiProject Food and drink. You can find the related request for tagging here . Maximum and careful attention was done to avoid any wrongly tagging any categories , but mistakes may happen... If you have concerns , please inform on the project talk page -- TinucherianBot ( talk) 01:12, 4 July 2008 (UTC)
Which source is correct? Sigma-Aldrich is quoting different pKa values at 25oC (for K-phosphates)
(1) 2.15, (2) 6.82, (3) 12.38 (phosphoric acid)
http://www.sigmaaldrich.com/catalog/search/ProductDetail/SIGMA/P8416
I've also check the Handbook of chemistry and Physics 52nd edition (1971-1972) which gives 2.12, 7.21, 12.67 -same as those used in this article- so I assume the values here are from the handbook. The infobox refrences should be made clearer.
I'm inclined to trust Sigma-Aldrich as theirs are probably more recent. I guess it must be different for differnt salts (e.g. just the phosphates (aq) for kotassium phosphate salts, ammonium salts, sodium salts etc) But i don't see how they can differ so much?
There were no error values in either source - "values without error-bars are like products without brand-names!"
—Preceding
unsigned comment added by
129.11.62.201 (
talk)
13:50, 18 August 2008 (UTC)
There's actually inconsistencies between the Ka values listed in the equations and the corresponding pKa listed in the succeeding paragraph. I'm inclined to believe the values in the paragraph since it matches the values on the phosphate page, but would anyone like to confirm? Seraphchoir ( talk) 21:10, 25 February 2013 (UTC)
The dissociation constants and pKa values are both provided by old editions of the CRC Handbook, as per the reference I have added. The newer editions (since the 74th) supply different pKa values and even give a reference for their data, but do not give values for the dissociation constants themselves. To avoid a technical WP:OR issue I have stuck with the old values, but if others feel more comfortable with supplying manually-calculated values the most recent CRC Handbook (96th ed.) gives pKa as 2.16, 7.21, 12.32. 130.216.208.173 ( talk) 04:55, 14 March 2016 (UTC)
What's up with these formulas??
"3NaCl(s) + H3PO4(l) -> NaH2PO4(s) + HCl(g)
3NaBr(s) + H3PO4(l) -> NaH2PO4(s) + HBr(g)
3NaI(s) + H3PO4(l) -> NaH2PO4(s) + HI(g)"
Does those two remaining units of halide-salt somehow go up in smoke and disappear from the universe? In these "reactions" they seem to do just that.
The only way I can think of to make sense of this is to view it as that it says that only one unit of salt can react and create a hydrogen halide despite the acid having 3 hydrogen atoms. (Which may not even be true) But you can't really put 3units in a formula describing a reaction if 2 of them actually don't take any part in said reaction....
Who wrote the formula(s), and what was it intended to mean? Or was it simply copied from some obscure & unreliable internet site without any verification whatsoever? —Preceding unsigned comment added by 90.227.181.98 ( talk) 15:47, 23 August 2008 (UTC)
I think some redistribution of text between Rust, Rustproofing and Rust removal is needed. Biscuittin ( talk) 16:25, 22 May 2009 (UTC)
What is food-grade phosphoric acid made from and how is it made? The article says it is a "mass-produced chemical" but no indication is provided as to how it is produced and from which materials. Badagnani ( talk) 23:49, 30 August 2009 (UTC)
Can we get a photo of the actual acid? Badagnani ( talk) 05:40, 28 November 2009 (UTC)
Should there be mention of the fact that Phosphoric Acid is also known as "Naval Jelly"?
216.146.231.6 ( talk) 23:22, 19 October 2015 (UTC)Dave
Please add the following to the Wikipedia page for Phosphoric acid.
In 'Uses' on the end of the 'Food Additive' section
"Phosphoric acid has also been linked to decay of tooth enamel, due to its low PH."
Here is the relevant reference to substantiate the claim.
http://www.nature.com/bdj/journal/v193/n10/full/4801628a.html — Preceding unsigned comment added by 92.14.180.33 ( talk) 19:42, 29 June 2017 (UTC)
Thanks Jpgordon,
Dan — Preceding
unsigned comment added by
92.14.180.33 (
talk)
20:01, 29 June 2017 (UTC)
Although H
3PO
4 isn't a strong acid, it can dissolve tungsten.
80.98.179.160 (
talk)
19:16, 27 March 2018 (UTC)
The correct E number is E337 (not E338 and definitely not an antioxidant. How can this error be corrected? I can't find "E number" in the article text for the chembox. Petergans ( talk) 08:15, 13 August 2018 (UTC)
The E number is E338 as per ref 13 & Wikipedia's list of E numbers. Its function is usually acid. I can't figure out how to revert the change!
MGSpiller (
talk)
15:29, 11 October 2018 (UTC)
![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Also known as Mofoic acid —Preceding unsigned comment added by 146.6.80.58 ( talk) 23:20, 14 October 2007 (UTC)
Other interesting information could be: Phosphoric acid producers, such as Thermphos International B.V. (www.thermphos.com)
And about Phosphate esters, these are not made from H3PO4 but from P2O5 (Phosphorus pentoxide), PPA (Polyphosphoric acid: highly concentrated phosphoric acid) or POCl3 (Phosphorus oxychloride). I wouldn't mention them here.
Else: there are several ways to produce phosphoric acid, from Wet acid (green acid) that is obtained through the sulphur process described here, but also through a Thermal process, that produces very pure phosphoric acid through the reaction of Water with elemental phosphorus (Yellow phosphorus).
- MahRain. 14 november 2005.
IMHO this article is a real mess:
1. It barely touches on the actual subject of phosphoric acids (of which there are an infinite number in a very rich structural system, but 3 important ones, ortho-, meta- and pyro-);
2. Yet it lurches off to discuss irrelevancies like eutrophication from phosphate detergents (this isn't the phosphate article!) while missing all but one or two of the many uses for this important material;
3. It introduces a lot of dubious material which will need fact checking (local anaesthetic?! colour me very skeptical);
4. It is totally disorganised (section "Chemical properties" contains no chemical properties, section "Preparation of phosphoric acid" contains 11 words on one method of preparation while the whole rest of the section is totally unrelated, etc). I suggest hydrochloric acid might make a good template;
5. The section "Processed food use" is at best POV (agro-industrial chemical ?!? They don't use fertiliser grade acid in colas!) and probably just wrong (citric acid ... obtainable from lemons and limes--sorry, nope, it's an agro-industrial chemical made by the Aspergillus niger mould fermenting scrap molasses and waste starch hydrolysates, and it works best if you add some ... phosphoric acid!);
6. The section "Effects on bone calcium" seems very suspicious. In particular, the claim When an excess of phosphorus (through phosphoric acid, for example) is introduced, the body's chemical balance mechanisms will attempt to maintain the proper calcium-phosphorus ionic ratio by extracting calcium from the bones is exactly the opposite of what would be expected from Le Chatelier's principle and not what is expected for normal homeostasis, but hey, biology is a funny thing, if someone comes up with a reputable cite I'll believe it. If not, I'll remove it. I'm foreshadowing all this here because I have a really long backlog and it might be a while before I get to it. Anyone else, please jump in first if you can. -- Securiger 11:21, 28 Mar 2005 (UTC)
I just deleted the detergent stuff. Phosphoric acid is not phosphate and it is not used in detergent.
The edits made by 152,163.100.66 on June 24, 2006 were actually made by me, H Padleckas. It appeared to me as if I was logged on, which is how I usually make my edits, but somehow only the IP address is listed in the contributions history. 152.163.100.130 14:46, 24 June 2006 (UTC) H Padleckas 15:10, 24 June 2006 (UTC)
A very old rust stripping method uses zinc and sulphuric acid. The steel part is immersed in water in contact with a piece of scrap zinc casting. A little battery acid is added. Add acid until after a few minutes bubbles can be seen coming off the steel. Leave the work in the solution until rust removal is seen to be complete. Remove and wash. Protect from re-rusting immediately, as the steel will be in a very rustable condition. Also remove and wash the zinc for later use or the remaining acid will simply corrode it away to nothing. Pays to mechanically remove flaking rust first or you will simply be using up chemical and zinc for no good reason. This method works very well for pieces of all sizes but it does pay not to load the solution with lots of bits as it seems to slow down rust removal quite substantially, possibly because it is not easy to ensure good electrical contact between lots of bits and the zinc. Use of a steel sieve is really helpful for stripping small parts as this acts as a good contact. Happy stripping. Evan. —Preceding unsigned comment added by 125.237.171.82 ( talk) 07:57, 8 June 2008 (UTC)
The article currently claims that phosphoric acid is used as an anesthetic. Can anyone confirm or deny this?
Darrien 08:42, 2005 May 14 (UTC)
I am an assistant professor of anesthesia at a Canadian teaching hospital. I have never heard of phosphoric acid used as a local anesthetic. Gresch, May 2, 2006, 17:40 UTC
Is he sure he didn't mix up "cyclopropane" with "orthophosphoric"? 68.231.189.108 ( talk) 01:08, 30 October 2009 (UTC)
5. i have just finished reading a book about phosphorus and its compounds. from what i've read so far, calcium deficiency is not the main cause for the bone degeneration, but lack of phosphates.
Was that one of the above editors, accidentally logged out by timeout? The wiki syntax was messed up so I reverted, so I don't think it was a regular editor. - Leonard G. 05:34, 8 September 2005 (UTC)
This imho reliable source http://physchem.ox.ac.uk/MSDS/PH/phosphoric_acid.html gives a different melting point for phosforic acid (21C instead of 42C).
Acros, a big supplier of fine chemicals, also lists 21C on their website.
The same sources give also a different density (1.68 in stead of 1.9) and boiling point (158C vs 213)
From what I understand the dispute seems to be over the effect of phosphoric acid on osteoporosis. The article cites few or no sources, so I'd like to add the following:
But I am unfamiliar with citing practices for non-website sources. —Preceding unsigned comment added by Tzenes ( talk • contribs) 14:34, 12 April 2006
One weak study involving only 30 women studied for the duration of a week does not trump all of those studies, even if it is mischaracterized as "a bunch of studies"
Why is phosphoric acid used in soft drinks?
Norm
It's cheap, non-toxic, highly water-soluble, not too strongly acidic, and gives the kind of sour taste some people probably like. Citric acid, which has some similar properties, is also used in some soft drinks. H Padleckas 20:21, 25 June 2006 (UTC)
This article's got some poor wording. "the skeletal effects of carbonated soft drink consumption are likely due primarily to milk displacement."? Uh...Garbage. Even if the study *citing* it say s it, it's garbage. "Milk" is not necessarily a dietary staple.
Come to think, I'm a bit shocked we're even talking about studies by Pepsi. They're obviously in conflict of interest to the point of being unreliable. 216.14.79.3 ( talk) 19:12, 12 August 2009 (UTC)Ubiquitousnewt
Quoting from the section "Biological effects on bone calcium and kidney health": "On the other hand, another study suggests that insufficient intake of phosphorus leads to lower bone density. The study does not examine the effect of phosphoric acid, which binds with magnesium and calcium in the digestive tract to form salts that are not absorbed, but rather studies general phosphorus intake.[4]". The rest of the articles focus on urinary products rather than digestive products. Would testing urine alone show a measurable precipitation of magnesium or calcium and phosphate salts if it happened somewhere in the digestive system? I thought you would require testing of more solid excretia. Is it possible the section could be summarized in one or two sentences and the rest thrown in discussion or put under more pertinent wikipedia article? There only seems to be one mention of relation to kidney health in the four paragraphs dedicated to "Biological effects on bone calcium and kidney health" and that was of calciuria. Is that to imply that if calcium is excreted via the urinary tract that you are more likely to get Kidney stones? If so, why not cite an article that says it rather than implying it. The lay reader, i.e., me, sees Kidney in the subtitle and expects to see a reference to kidney in the text indicating which part is pertinent to kidney health. Normally, debatable or unproven research results would not be included in an encyclopedia. If you have to imply it, then you probably have insufficient proof, ergo, not encyclopedic. I am not a chemist, biochemist or health professional so I will leave the editing to those with more qualification for editing. Added by Danny Robinson, New Zealand — Preceding unsigned comment added by 119.224.98.136 ( talk) 00:23, 20 February 2012 (UTC)
The following suggestions were generated by a semi-automatic javascript program, and may or may not be accurate for the article in question.
You may wish to browse through User:AndyZ/Suggestions (and the javascript checklist; see the last paragraph in the lead) for further ideas. Thanks, Wim van Dorst ( Talk) 21:10, 26 June 2006 (UTC)
In the final paragraph, this subsection discusses the dehydration of phosphoric acid. That phosphoric acid can be dehydrated by heating to metaphosphoric acid is supported by numerous references that I have found (though there is no mention in the article of the intermediate form of pyrophosphoric acid, which nearly every reference does mention). But the paragraph goes on to say that further dehydration leads to phosphoric anhydride (P4H10). This is, in a sense, true, since chemical dehydration of metaphosphoric acid will lead to this, but in the context of this sentence, it suggests that further heating would cause further dehydration. I can find no reference to support that -- indeed Merck 9th ed. says that metaphosphoric acid volatilizes at red heat. Hence it would be well nigh impossible to dehydrate metaphosphoric acid by heating. Karlhahn 14:21, 23 September 2006 (UTC)
What you are looking for might be difficult to find. I recommend deleting the paragraph that you suspect is misleading and re-writing it based on the facts known to you.-- Smokefoot 15:01, 23 September 2006 (UTC)
You can get futher dehydration of some of the acid salts of phosphoric acid by heating: this is used to make superphosphate fertilizers. From vague memory, I think that metaphosphic acid is the limit for dehydration of the free acid, but, even disregarding the vagueries of my memory, the experimenters may well have missed higher acids (I bet no-one has looked at the question for several decades). I would look and see what you can find on superphosphates, that may give an idea of what happens to the free acid. Physchim62 (talk) 13:21, 25 September 2006 (UTC)
Will elèctròlusis work? -lysdexia 14:05, 10 October 2007 (UTC)
Whoever thought this supported their claim was very wrong.
Here is the reaction of Phosphoric Acid with Calcium:
2 H3PO4 + 3 Ca(OH)2 -> 6 H(OH) + Ca3(PO4)2
According to Le Chatelier's principle, if you add more H3PO4, it pushes the reaction to the right which consumes more calcium.
According to Le Chatelier's principle, if this reaction consumes unbound calcium in the digestive tract, more will be freed from the bone.
The above assumes that bone is in equilibrium with the digestive tract, which is far from the case... It also assumes only two species, also incorrect. Physchim62 (talk) 10:32, 15 January 2007 (UTC)
This article seems to hold a bias in support of Tucker et al. I would recommend presenting Tucker as a counter study to Elmstål, removing the exhaustive discussion of Tucker (from "This is Tucker..." to "...needed to confirm the findings." and leaving it as a reference as is done for the other studies. This discussion is redundant to the citation and biases the article toward this study by presenting it is a more dignified manner. "This is Tucker..." is akward syntactically. mDonaldson 03:56, 15 January 2007 (UTC)
What do you think about this image? Should it be added to "Preparation.." section? Abelin C A usesobad 07:17, 17 January 2007 (UTC)
My mom wants to replenish an old bottle of Dent-U-Care denture cleaner.
It states on bottle "WARNING" "contains phosphoric acid" as the only listed ingredient.
My search produced 2 red flags:
any input on this appreciated
-- Mamatops 22:30, 13 September 2007 (UTC)
Is Image:Luc Viatour phosphore poudre.jpg a picture of phosphoric acid? Calliopejen1 21:27, 15 September 2007 (UTC)
Why it is called orthophosphoric acid instead of phosphoric acid? Can anyone give me th answare? Thanks
Is this really even appropriate for this article?
I mean, a mention of possible health effects is alright, but is this long (dubiously researched) passage on whether or not your bones will melt if you drink soda necessary? Jgr2 ( talk) 16:28, 25 March 2008 (UTC)
I'd say it's valid. That's the reason I looked this article up. The alternative would be for this article to have a link to a separate article that talks about that. 71.92.101.14 ( talk) 05:12, 28 October 2009 (UTC)
This article talk page was automatically added with {{ WikiProject Food and drink}} banner as it falls under Category:Food or one of its subcategories. If you find this addition an error, Kindly undo the changes and update the inappropriate categories if needed. The bot was instructed to tagg these articles upon consenus from WikiProject Food and drink. You can find the related request for tagging here . Maximum and careful attention was done to avoid any wrongly tagging any categories , but mistakes may happen... If you have concerns , please inform on the project talk page -- TinucherianBot ( talk) 01:12, 4 July 2008 (UTC)
Which source is correct? Sigma-Aldrich is quoting different pKa values at 25oC (for K-phosphates)
(1) 2.15, (2) 6.82, (3) 12.38 (phosphoric acid)
http://www.sigmaaldrich.com/catalog/search/ProductDetail/SIGMA/P8416
I've also check the Handbook of chemistry and Physics 52nd edition (1971-1972) which gives 2.12, 7.21, 12.67 -same as those used in this article- so I assume the values here are from the handbook. The infobox refrences should be made clearer.
I'm inclined to trust Sigma-Aldrich as theirs are probably more recent. I guess it must be different for differnt salts (e.g. just the phosphates (aq) for kotassium phosphate salts, ammonium salts, sodium salts etc) But i don't see how they can differ so much?
There were no error values in either source - "values without error-bars are like products without brand-names!"
—Preceding
unsigned comment added by
129.11.62.201 (
talk)
13:50, 18 August 2008 (UTC)
There's actually inconsistencies between the Ka values listed in the equations and the corresponding pKa listed in the succeeding paragraph. I'm inclined to believe the values in the paragraph since it matches the values on the phosphate page, but would anyone like to confirm? Seraphchoir ( talk) 21:10, 25 February 2013 (UTC)
The dissociation constants and pKa values are both provided by old editions of the CRC Handbook, as per the reference I have added. The newer editions (since the 74th) supply different pKa values and even give a reference for their data, but do not give values for the dissociation constants themselves. To avoid a technical WP:OR issue I have stuck with the old values, but if others feel more comfortable with supplying manually-calculated values the most recent CRC Handbook (96th ed.) gives pKa as 2.16, 7.21, 12.32. 130.216.208.173 ( talk) 04:55, 14 March 2016 (UTC)
What's up with these formulas??
"3NaCl(s) + H3PO4(l) -> NaH2PO4(s) + HCl(g)
3NaBr(s) + H3PO4(l) -> NaH2PO4(s) + HBr(g)
3NaI(s) + H3PO4(l) -> NaH2PO4(s) + HI(g)"
Does those two remaining units of halide-salt somehow go up in smoke and disappear from the universe? In these "reactions" they seem to do just that.
The only way I can think of to make sense of this is to view it as that it says that only one unit of salt can react and create a hydrogen halide despite the acid having 3 hydrogen atoms. (Which may not even be true) But you can't really put 3units in a formula describing a reaction if 2 of them actually don't take any part in said reaction....
Who wrote the formula(s), and what was it intended to mean? Or was it simply copied from some obscure & unreliable internet site without any verification whatsoever? —Preceding unsigned comment added by 90.227.181.98 ( talk) 15:47, 23 August 2008 (UTC)
I think some redistribution of text between Rust, Rustproofing and Rust removal is needed. Biscuittin ( talk) 16:25, 22 May 2009 (UTC)
What is food-grade phosphoric acid made from and how is it made? The article says it is a "mass-produced chemical" but no indication is provided as to how it is produced and from which materials. Badagnani ( talk) 23:49, 30 August 2009 (UTC)
Can we get a photo of the actual acid? Badagnani ( talk) 05:40, 28 November 2009 (UTC)
Should there be mention of the fact that Phosphoric Acid is also known as "Naval Jelly"?
216.146.231.6 ( talk) 23:22, 19 October 2015 (UTC)Dave
Please add the following to the Wikipedia page for Phosphoric acid.
In 'Uses' on the end of the 'Food Additive' section
"Phosphoric acid has also been linked to decay of tooth enamel, due to its low PH."
Here is the relevant reference to substantiate the claim.
http://www.nature.com/bdj/journal/v193/n10/full/4801628a.html — Preceding unsigned comment added by 92.14.180.33 ( talk) 19:42, 29 June 2017 (UTC)
Thanks Jpgordon,
Dan — Preceding
unsigned comment added by
92.14.180.33 (
talk)
20:01, 29 June 2017 (UTC)
Although H
3PO
4 isn't a strong acid, it can dissolve tungsten.
80.98.179.160 (
talk)
19:16, 27 March 2018 (UTC)
The correct E number is E337 (not E338 and definitely not an antioxidant. How can this error be corrected? I can't find "E number" in the article text for the chembox. Petergans ( talk) 08:15, 13 August 2018 (UTC)
The E number is E338 as per ref 13 & Wikipedia's list of E numbers. Its function is usually acid. I can't figure out how to revert the change!
MGSpiller (
talk)
15:29, 11 October 2018 (UTC)