Carboxylate: Difference between revisions

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General Fixes using AWB
m (General Fixes using AWB)
 
== Resonance stabilization of the carboxylate ion==
Carboxylic acids easily dissociate into a carboxylate anion and a positively charged hydrogen ion (proton), much more readily than alcohols do (into an [[alkoxide]] ion and a proton), because the carboxylate ion is stabilized by [[Resonance (chemistry)|resonance]]. The negative charge that is left after [[deprotonation]] of the carboxyl group is delocalized between the two [[electronegative]] oxygen atoms in a resonance structure.
 
:[[File:Carboxylate-resonance-2D.png|400px|Equivalence of the resonance forms the delocalised form of a general carboxylate anion]]
 
This [[delocalization]] of the electron cloud means that either of the oxygen atoms is less strongly negatively charged; the positively charged proton is therefore less strongly attracted back to the carboxylate group once it has left. In contrast, an alkoxide ion, once formed, would have a strong negative charge on the oxygen atom, which would make it difficult for the proton to escape. Thus, the carboxylate ion is more stable and carboxylic acids have a lower [[pH]] than alcohols: the higher the number of protons in solution, the lower the pH. <ref>{{cite book | author= Fox, Marye Anne; Whitesell, James K. | year = 1997 | title = Organic Chemistry | edition = 2| publisher = Jones and Bartlett Publishers | location = Sudbury, Massachusetts| isbn = 0-7637-0178-5 }}</ref>
 
==Uses==
Polycarboxylate ethers serve as the main component of [[Superplasticizer|superplasticizerssuperplasticizer]]s, admixtures used in the [[construction industry]].
 
==Examples==
[[Category:Carboxylate anions| ]]
 
[[fr:Acide carboxylique#Ions carboxylates]]
[[de:Polycarboxylate]]
[[fr:Acide carboxylique#Ions carboxylates]]