Talk:Salt metathesis reaction

Doubting but not certain of the CuSO4 + NaCl example under "aqueous metathesis"

I believe that the example of copper sulfate + sodium chloride precipitating copper chloride is incorrect - At saturation, the solution would be ~2M in copper ion and sulfate, and 5.8M in Na+ and Cl-, but the solubility of CuCl2 is ~5.2M, so it's about halfway to saturated in CuCl2. Sodium sulfate should precipitate though.

OTOH, it's been a couple months since I finished general chemistry, so I'm not willing to edit it just yet.

71.36.200.118 05:25, 30 January 2007 (UTC) EJK

I'll look at it; i'm not too sure what the direction was of the author, so it'll take a few mins to see what he's after. J O R D A N ^[talk ] 08:43, 30 January 2007 (UTC)

Move

Move because no disambiguation necessary. --Rifleman 82 01:53, 15 October 2007 (UTC)

Citation involving the "Double-Replacement" terminology

I don't know how it ought to be cited, but I'm a student at Advanced Technologies Academy, and I know that in the chemistry courses they teach here, "Double-Replacement" is the term encouraged. Perhaps just take off the [citation needed] tag? —Preceding unsigned comment added by 169.241.64.231 (talk) 19:43, 25 March 2009 (UTC)

Perhaps a better term would be "not discouraged," as it seems that the norm is for old terminology to be discouraged in favor of new terminology. At my college, both metathesis and double displacement are acceptable terms.Ginogrz (talk) 02:02, 7 July 2009 (UTC)

Misleading picture

The first picture has an equation mark instead of regular horizontal arrow, some people may think its a double bond between hydrogen and chlorine, which is slightly imposible... —Preceding unsigned comment added by Andowero (talk • contribs) 18:54, 12 May 2010 (UTC)
A horizontal arrow is the standard for any chemical equation, because it represents the reaction. A set of reactants yield a set of products. —Preceding unsigned comment added by 131.91.78.64 (talk) 13:20, 18 May 2011 (UTC)

The replacement image is still using the "equals" sign and the use of the down-arrow to indicate precipitation clearly indicates that the illustrated idea is the change--the reaction going forward--not a simple equivalence. My other quibble is that it is not quite clear what item has each given charge--would be clearer if color-coding were used consistently. A similar diagram should be easy to cook up in svg or tex to make it easy to adjust all these types of details. Inded, the disputed picture was already removed once before. Here is the problematic one (1) and three alternatives (2–4):

1.

2. ${\color {Orange}Ag}{\color {Blue}NO_{3}}+{\color {Green}H}{\color {Magenta}Cl}\rightarrow {\color {Green}H}{\color {Blue}NO_{3}}+{\color {Orange}Ag}{\color {Magenta}Cl}\downarrow$

3. ${\color {Orange}{\overset {+1}{Ag}}}{\color {Blue}{\overset {-1}{NO_{3}}}}+{\color {Green}{\overset {+1}{H}}}{\color {Magenta}{\overset {-1}{Cl}}}\rightarrow {\color {Green}{\overset {+1}{H}}}{\color {Blue}{\overset {-1}{NO_{3}}}}+{\color {Orange}{\overset {+1}{Ag}}}{\color {Magenta}{\overset {-1}{Cl}}}\downarrow$

4. ${\overset {+1}{\color {Orange}Ag}}{\overset {-1}{\color {Blue}NO_{3}}}+{\overset {+1}{\color {Green}H}}{\overset {-1}{\color {Magenta}Cl}}\rightarrow {\overset {+1}{\color {Green}H}}{\overset {-1}{\color {Blue}NO_{3}}}+{\overset {+1}{\color {Orange}Ag}}{\overset {-1}{\color {Magenta}Cl}}\downarrow$

Any of 2–4 are better than 1; the charges are a nice touch (3 & 4), illustrating how it's the same ionic units (not just the same atoms) swapping (no covalent or redox issues). At first I liked using the same color to illustrate which atom-group is which charge (3), but now I'm not sure if it makes the charge appear to be part of the formal way of writing the atom-group rather than being an annotation about it (4). I'm going to put #4 in the article because it's closest to what's there now (most recent insertion requested improvements), but would love to hear others' opinions (and because it's TeX feel free to suggest alternate colors, etc.). DMacks (talk) 15:22, 2 July 2012 (UTC)

"=" symbol is used to denote a stoichiometric relation. So it is no problem. also because in China，right arrow is not allowed in inorganic balanced equation，the chinese user may be use = to contribute to wikicommons.Zt610152145 (talk) 13:37, 21 August 2012 (UTC)

zh.wikipedia seems to use the right-arrow consistently in balanced inorganic reactions in its chemical articles. At least in English stoichiometry and balanced reactions are still written with arrows: they indicate the verb of the reaction, not just the two sides being somehow "equal". DMacks (talk) 15:34, 21 August 2012 (UTC)

Denoting the phase with (aq) is pretty important in this instance too. We don't really have discrete silver nitrate molecules floating around. --Rifleman 82 (talk) 15:51, 21 August 2012 (UTC)

"Easy to resolve these sorts of concerns" is another advantage of using text markup rather than an image:) Obviously feel free to update the mathtex in the article, and maybe propose the image itself for deletion if it has "factual" (as opposed to stylistic) problems. DMacks (talk) 16:06, 21 August 2012 (UTC)

there is no standard for chemical equation in zhwiki now, and some article is translated from enwiki. my general chemistry book said "=" indicated the amount of reactants and products is the same. if in enwiki it is unacceptable, i respects the common use of english, but this picture is not wrong anyway.Zt610152145 (talk) 18:34, 28 August 2012 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page or in a move review. No further edits should be made to this section.

The result of the move request was: moved. Unopposed for over two weeks. Jenks24 (talk) 10:12, 30 June 2012 (UTC)

---

Salt metathesis reaction → Double replacement reaction – "Metathesis" is an archaic term. "Double replacement" or "double displacement" is what it goes by nowadays. Relisted. Jenks24 (talk) 07:04, 22 June 2012 (UTC) Whoop whoop pull up ^{Bitching Betty | Averted crashes} 18:34, 14 June 2012 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Sorry I missed the discussion, but take a look at terms used in the last 10 years [1], [2], and [3]. To me at least, "double replacement" is the most obscure. The most contemporary term used is "salt metathesis". I've heard of "double displacement", but it's supposedly as deprecated as "double decomposition". I'm aware that this page was listed by a bot in WT:CHEMISTRY but I am concerned that it did not get enough discussion. I'll ask the community to take a look at this in particular; in the mean time, my view is that metathesis is the most accurate and contemporary, and is the term used in the Gold Book. --Rifleman 82 (talk) 14:00, 21 August 2012 (UTC)

I also missed this discussion. "Double displacement" is old fashioned terminology, maybe a high school term. "Salt metathesis" is more contemporary in the journals and conversationally by practicing chemists. --Smokefoot (talk) 15:17, 21 August 2012 (UTC)

Me too. I think it should have stayed where it was. Chris (talk) 18:34, 21 August 2012 (UTC)

Poor description

"is a type of molecular process involving the exchange of bonds between the two reacting chemical species, "

It seems to me this should be better described. In the cases mentioned where there are solutions of two salts being mixed, the bonds between the original materials have already been broken by the process of solution and are no longer in existed to be "exchanged".Eregli bob (talk) 07:16, 26 July 2012 (UTC)

Transesterification = a double-displacement??

I was just studying the mechanism of Transesterification and, unless I'm mistaken on what exactly precisely constitutes a double-displacement (salt-metathesis), I think it may count as an example that may be worth noting. Albeit, it is *not* an ionic salt exchange, but instead covalent trades between an alcohol and an ester, but that seems to be covered in the main Salt Metathesis article, when it says "The bond between the reacting species can either be ionic or covalent."

I'm tempted to add a section into the Types of Reactions section, showing that transesterification counts as an example, but don't want to mislead anyone if the strict chemical basis for double-displacement disallows for this reaction mechanism.

If you have further info on whether yes, it does, or no, it does not, please let me know on my talk page. PolymathGirl (talk) 17:58, 18 June 2017 (UTC)

I wouldnt add it, although your observations are insightful. My reasoning: (1) salt metathesis is really intended for salt-like reagents, (2) Wikipedia guidelines urge us not to make it into a textbook. The encylopedia is intended to give and explain facts, but not to go much farther. Also, most readers might not be as insightful as you, so they'd be confused. But no one is in charge here, so follow your instincts. --Smokefoot (talk) 19:21, 18 June 2017 (UTC)

Sodium bicarbonate or carbonate?

in the section on acid - base reactions

equation shows carbonate, but text is talking about bicarbonate — Preceding unsigned comment added by Polypipe Wrangler (talk • contribs) 07:22, 6 March 2024 (UTC)