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Note to anybody editing the table: If you add a line to the table, or change a line, please be sure to cite your data source. Various sources disagree when it comes to solubility product data. Hence without citing a source, any data placed in the table is meaningless. The table has a data source column for that reason. Karlhahn 22:47, 13 December 2006 (UTC)
Not bad. I'm going to do some editing myself though, to Wikify a little and also perhaps get things that don't always dissociate completely and so readily as sucrose (maybe an organic acid). Its certainly better than before. EagleFalconn 20:45, 7 Dec 2004 (UTC)
I like it, but it does seem to leave out solid state chemistry. I don't see an obvious way to fix that now, but perhaps I'll come back to it. Articles such as precipitation strengthening could use a link here; I'll work on that for now.-- Joel 03:58, 5 August 2005 (UTC)
== merger ==
I put the merger notice; is there really a good reason to have a separate solubility equilibrium article than solubility. There seems to be a lot of overlap in both. Olin
I realize the merger was rejected (although more by non-votes than actual votes), but I will express my opinion more completely, and let the crowd decide. I still don't understand the allure of having two articles. Solubility equilibrium is always associated with solubility, and is a proper subtopic. There are a lot of chemistry articles that are quite fragmented, and it would be nice to have some larger, coherent articles.
Furthermore, why should solubility have a solubility equilibrium article? Should we have an electron transfer equilibrium article and a redox reaction article? If you were looking in an encyclopedia, would you really look up solubility equilibrium? (The solubility of gases in liquids and other above solubilities are equilibrium processes.) I will admit, there is no Wikipedia policy to go by here (just my opinion!), and hence I will let it lie, but I just wanted to express my opinion more completely. Olin 20:40, 28 March 2006 (UTC)
I think that solubility equilibrium should merge with equilibrium constant, and that page should have a solubility product constant inside the solubility equilibrium section. In fact, I was going to link to it in my post on the discussion of the redox page. Kr5t 02:36, 29 March 2006 (UTC)
I believe the pages should be merged. Solubility equilibrium is directly linked to chemical equilibrium and should be placed on the same page in its own sub-section. If, however, someone is to create a comprehensive solubility equilibrium constant table, the page should remain as it is. marcpatt14, May 2006
strongly oppose merger. these are both big topics and very different topics. if anything we need more articles such as total dissoved solids, a major topic in water quality analysis within environmental science Anlace 15:01, 10 June 2006 (UTC)
The following is a rough draft of a sol-prod table (from Lange's and CRC) that I will be adding to the article once I've finished proofreading it Karlhahn 01:34, 28 August 2006 (UTC).
Table has now been moved to main page Karlhahn 01:15, 30 August 2006 (UTC)
A casual observer may struggle to understand whether a compound with a high or low solubility constant was the most soluble. Does a high solubity constant indicate the most soluble? Maybe this should be clarified. King of Leon 16:57, 9 May 2007 (UTC)
---- indeed it does, if the solubility is greater than 1 its very very soluble, if it has less than 1 its less soluble most substances have a very low solubility < 10^-5 . but yes a higher Ksp means more solubility less Ksp means more insolubility
Equations
The development of the solubility product equation for CaSO4 is unclear. All of a sudden K is under square root, but no explanation of how it ends there.
This becomes clear below, however that equation as well or rather its development is also unclear. I think this article is very important but needs a lot of help.-- Goobysam ( talk) 20:56, 7 January 2009 (UTC)
umm, i was looking up the accepted Ksp value for Ca(OH)2 for a lab, and i noticed wikipedia gives 2 values for it, 4.68 × 10−6 on the Calcium Hydroxide page, and 8.0 × 10−6 on the chart on this page. which one would be correct? these things should be looked into in order to remove discrepencies. 74.104.255.195 23:41, 17 May 2007 (UTC)
alright thankyou 74.104.255.195 21:34, 19 May 2007 (UTC)
it seems that the units are missed out throughout the context shouldn't solubility products have the units like mol dm-3, mol2 dm-6, mol3 dm-9, etc (depending on the number of ions in the compound) 218.215.27.145 13:19, 20 June 2007 (UTC)
I added a section on if the mole ratios are not even. it needs a little tidying up but the facts are solid hope someone finds it useful. —Preceding unsigned comment added by 83.42.216.20 ( talk) 17:42, 30 January 2008 (UTC)
nope not atall you did a great job, thanks. —Preceding unsigned comment added by 88.24.15.38 ( talk) 19:05, 26 May 2008 (UTC)
Ill put up a derivation. —Preceding unsigned comment added by 82.1.253.112 ( talk) 22:08, 21 November 2009 (UTC)
I think that the general fomula
is wrong. I don't know where it comes from.
The solubility product for a general binary compound ApBq is given by
When the product dissociates the concentration of B is equal to q/p times the concentration of A.
Therefore
The solubility is 1/p [A]
The text has been extensively revised and new sections added. There is overlap with the article solubility, but my feeling is that there is no need to merge these articles. Petergans ( talk) 08:43, 7 July 2010 (UTC)
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In the "Dissolution with dissociation" section, "ionic compounds" subsection, there is an explanation of calculating solubility in terms of Ksp and a table of how this works for various compounds.
In this table, it is stated that the solubility expression for calcium sulphate (CaSO4) is stated to be (Ksp/16)^0.25 and the solubility expression for Iron Phosphate (FePO4) is stated to be (Ksp/729)^(1/6).
Since "p" and "q" are based on stoichiometric constants and not on charge, should the solubility expression not be (Ksp)^0.5 for both compounds?
158.194.9.137 ( talk) 14:47, 2 November 2017 (UTC)
You are right! Many thanks for the observation. I have revised section concerned. Petergans ( talk) 15:12, 9 November 2017 (UTC)
I think that some cases where activities are needed in calculations for the system solid salt-solvent should be mentioned by the article.-- 82.137.14.73 ( talk) 21:05, 21 November 2017 (UTC)
The temperature dependence that was given
is unsourced and conflicts with the definition given in Denbeigh, "The principles of chemical equilibrium", page 308
where is the partial molar enthalpy of the electrolyte at infinite dilution and h' is the enthalpy per mole of the pure crystal.
Atkins, "Physical chemistry" p153 (8th edition) states that although solubility is not strictly a colligative property...
It is not clear that the two expressions (2) and/or (3) are equivalent to (1). A source citation will needed if expression (1) is to be reinstated. Petergans ( talk) 11:42, 10 July 2019 (UTC)
I notice that this article does not include info re the solubility equilibrium of substances in mixed solvents.-- 109.166.137.83 ( talk) 23:36, 19 July 2020 (UTC)
In the section regarding the solubility product, it is stated that, since in a calcium hydroxide solution the number of hydroxide anions is double the amount of calcium cations, the solubility product K_sp = [Ca2+][OH-]^2 reduces to K_sp = [Ca2+]^3.
How is this possible if the concentration of OH-, as previously stated, is double the concentration of Ca2+? Shouldn't the solubility product equal [Ca2+]{2*[Ca2+]}^2, and thus 4[Ca2+]^3?
This seems to be reinforced by the immediately following table.
Is this correct? 93.43.184.56 ( talk) 13:11, 17 November 2021 (UTC)
This is the
talk page for discussing improvements to the
Solubility equilibrium article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
This article is rated B-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | |||||||||||
|
Note to anybody editing the table: If you add a line to the table, or change a line, please be sure to cite your data source. Various sources disagree when it comes to solubility product data. Hence without citing a source, any data placed in the table is meaningless. The table has a data source column for that reason. Karlhahn 22:47, 13 December 2006 (UTC)
Not bad. I'm going to do some editing myself though, to Wikify a little and also perhaps get things that don't always dissociate completely and so readily as sucrose (maybe an organic acid). Its certainly better than before. EagleFalconn 20:45, 7 Dec 2004 (UTC)
I like it, but it does seem to leave out solid state chemistry. I don't see an obvious way to fix that now, but perhaps I'll come back to it. Articles such as precipitation strengthening could use a link here; I'll work on that for now.-- Joel 03:58, 5 August 2005 (UTC)
== merger ==
I put the merger notice; is there really a good reason to have a separate solubility equilibrium article than solubility. There seems to be a lot of overlap in both. Olin
I realize the merger was rejected (although more by non-votes than actual votes), but I will express my opinion more completely, and let the crowd decide. I still don't understand the allure of having two articles. Solubility equilibrium is always associated with solubility, and is a proper subtopic. There are a lot of chemistry articles that are quite fragmented, and it would be nice to have some larger, coherent articles.
Furthermore, why should solubility have a solubility equilibrium article? Should we have an electron transfer equilibrium article and a redox reaction article? If you were looking in an encyclopedia, would you really look up solubility equilibrium? (The solubility of gases in liquids and other above solubilities are equilibrium processes.) I will admit, there is no Wikipedia policy to go by here (just my opinion!), and hence I will let it lie, but I just wanted to express my opinion more completely. Olin 20:40, 28 March 2006 (UTC)
I think that solubility equilibrium should merge with equilibrium constant, and that page should have a solubility product constant inside the solubility equilibrium section. In fact, I was going to link to it in my post on the discussion of the redox page. Kr5t 02:36, 29 March 2006 (UTC)
I believe the pages should be merged. Solubility equilibrium is directly linked to chemical equilibrium and should be placed on the same page in its own sub-section. If, however, someone is to create a comprehensive solubility equilibrium constant table, the page should remain as it is. marcpatt14, May 2006
strongly oppose merger. these are both big topics and very different topics. if anything we need more articles such as total dissoved solids, a major topic in water quality analysis within environmental science Anlace 15:01, 10 June 2006 (UTC)
The following is a rough draft of a sol-prod table (from Lange's and CRC) that I will be adding to the article once I've finished proofreading it Karlhahn 01:34, 28 August 2006 (UTC).
Table has now been moved to main page Karlhahn 01:15, 30 August 2006 (UTC)
A casual observer may struggle to understand whether a compound with a high or low solubility constant was the most soluble. Does a high solubity constant indicate the most soluble? Maybe this should be clarified. King of Leon 16:57, 9 May 2007 (UTC)
---- indeed it does, if the solubility is greater than 1 its very very soluble, if it has less than 1 its less soluble most substances have a very low solubility < 10^-5 . but yes a higher Ksp means more solubility less Ksp means more insolubility
Equations
The development of the solubility product equation for CaSO4 is unclear. All of a sudden K is under square root, but no explanation of how it ends there.
This becomes clear below, however that equation as well or rather its development is also unclear. I think this article is very important but needs a lot of help.-- Goobysam ( talk) 20:56, 7 January 2009 (UTC)
umm, i was looking up the accepted Ksp value for Ca(OH)2 for a lab, and i noticed wikipedia gives 2 values for it, 4.68 × 10−6 on the Calcium Hydroxide page, and 8.0 × 10−6 on the chart on this page. which one would be correct? these things should be looked into in order to remove discrepencies. 74.104.255.195 23:41, 17 May 2007 (UTC)
alright thankyou 74.104.255.195 21:34, 19 May 2007 (UTC)
it seems that the units are missed out throughout the context shouldn't solubility products have the units like mol dm-3, mol2 dm-6, mol3 dm-9, etc (depending on the number of ions in the compound) 218.215.27.145 13:19, 20 June 2007 (UTC)
I added a section on if the mole ratios are not even. it needs a little tidying up but the facts are solid hope someone finds it useful. —Preceding unsigned comment added by 83.42.216.20 ( talk) 17:42, 30 January 2008 (UTC)
nope not atall you did a great job, thanks. —Preceding unsigned comment added by 88.24.15.38 ( talk) 19:05, 26 May 2008 (UTC)
Ill put up a derivation. —Preceding unsigned comment added by 82.1.253.112 ( talk) 22:08, 21 November 2009 (UTC)
I think that the general fomula
is wrong. I don't know where it comes from.
The solubility product for a general binary compound ApBq is given by
When the product dissociates the concentration of B is equal to q/p times the concentration of A.
Therefore
The solubility is 1/p [A]
The text has been extensively revised and new sections added. There is overlap with the article solubility, but my feeling is that there is no need to merge these articles. Petergans ( talk) 08:43, 7 July 2010 (UTC)
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Solubility equilibrium. Please take a moment to review
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Cheers.— cyberbot II Talk to my owner:Online 11:59, 2 April 2016 (UTC)
In the "Dissolution with dissociation" section, "ionic compounds" subsection, there is an explanation of calculating solubility in terms of Ksp and a table of how this works for various compounds.
In this table, it is stated that the solubility expression for calcium sulphate (CaSO4) is stated to be (Ksp/16)^0.25 and the solubility expression for Iron Phosphate (FePO4) is stated to be (Ksp/729)^(1/6).
Since "p" and "q" are based on stoichiometric constants and not on charge, should the solubility expression not be (Ksp)^0.5 for both compounds?
158.194.9.137 ( talk) 14:47, 2 November 2017 (UTC)
You are right! Many thanks for the observation. I have revised section concerned. Petergans ( talk) 15:12, 9 November 2017 (UTC)
I think that some cases where activities are needed in calculations for the system solid salt-solvent should be mentioned by the article.-- 82.137.14.73 ( talk) 21:05, 21 November 2017 (UTC)
The temperature dependence that was given
is unsourced and conflicts with the definition given in Denbeigh, "The principles of chemical equilibrium", page 308
where is the partial molar enthalpy of the electrolyte at infinite dilution and h' is the enthalpy per mole of the pure crystal.
Atkins, "Physical chemistry" p153 (8th edition) states that although solubility is not strictly a colligative property...
It is not clear that the two expressions (2) and/or (3) are equivalent to (1). A source citation will needed if expression (1) is to be reinstated. Petergans ( talk) 11:42, 10 July 2019 (UTC)
I notice that this article does not include info re the solubility equilibrium of substances in mixed solvents.-- 109.166.137.83 ( talk) 23:36, 19 July 2020 (UTC)
In the section regarding the solubility product, it is stated that, since in a calcium hydroxide solution the number of hydroxide anions is double the amount of calcium cations, the solubility product K_sp = [Ca2+][OH-]^2 reduces to K_sp = [Ca2+]^3.
How is this possible if the concentration of OH-, as previously stated, is double the concentration of Ca2+? Shouldn't the solubility product equal [Ca2+]{2*[Ca2+]}^2, and thus 4[Ca2+]^3?
This seems to be reinforced by the immediately following table.
Is this correct? 93.43.184.56 ( talk) 13:11, 17 November 2021 (UTC)