Editing Carboxylic acid (section)

==Examples and nomenclature==
Carboxylic acids are commonly identified by their [[trivial name]]s. They often have the suffix ''-ic acid''. {{anchor|-oic}}[[IUPAC]]-recommended names also exist; in this system, carboxylic acids have an ''-oic acid'' suffix.<ref>[http://www.acdlabs.com/iupac/nomenclature/79/r79_24.htm Recommendations 1979]. Organic Chemistry IUPAC Nomenclature. Rules C-4 Carboxylic Acids and Their Derivatives.</ref> For example, [[butyric acid]] ({{chem2|CH3CH2CH2CO2H}}) is butanoic acid by IUPAC guidelines. For nomenclature of complex molecules containing a carboxylic acid, the carboxyl can be considered position one of the [[parent chain]] even if there are other [[substituent]]s, such as [[3-chloropropanoic acid]]. Alternately, it can be named as a "carboxy" or "carboxylic acid" substituent on another parent structure, such as [[2-Furoic acid|2-carboxyfuran]].{{cn|date=May 2025}}

The carboxylate anion ({{chem2|R\sCOO−}} or {{chem2|R\sCO2−}}) of a carboxylic acid is usually named with the suffix ''-ate'', in keeping with the general pattern of ''-ic acid'' and ''-ate'' for a [[conjugate acid]] and its conjugate base, respectively. For example, the conjugate base of [[acetic acid]] is [[acetate]].{{cn|date=May 2025}}

[[Carbonic acid]], which occurs in [[bicarbonate buffer system]]s in nature, is not generally classed as one of the carboxylic acids, despite that it has a [[moiety (chemistry)|moiety]] that looks like a COOH group. {{cn|date=May 2025}}
{|class = "wikitable"
|+Straight-chain, saturated carboxylic acids (alkanoic acids)
!Carbon<br>atoms
!Common name
!IUPAC name
!Chemical formula
!Common location or use
|-<!--
|0 || [[Oxygen]] || ? || OO || [[Air]]
|- -->
|1 || [[Formic acid]] || Methanoic acid || HCOOH || [[Insect stings]]
|-
|2 || [[Acetic acid]] || Ethanoic acid || {{chem2|CH3COOH}} || [[Vinegar]]
|-
|3 || [[Propionic acid]] || Propanoic acid || {{chem2|CH3CH2COOH}} || Preservative for stored grains, [[body odour]], milk, butter, cheese
|-
|4 || [[Butyric acid]] || Butanoic acid || {{chem2|CH3(CH2)2COOH}} || [[Butter]]
|-
|5 || [[Valeric acid]] || Pentanoic acid || {{chem2|CH3(CH2)3COOH}} || [[Valerian (herb)|Valerian]] plant
|-
|6 || [[Caproic acid]] || Hexanoic acid || {{chem2|CH3(CH2)4COOH}} || [[Goat]] fat
|-
|7 || [[Enanthic acid]] || Heptanoic acid || {{chem2|CH3(CH2)5COOH}} ||Fragrance
|-
|8 || [[Caprylic acid]] || Octanoic acid || {{chem2|CH3(CH2)6COOH}} || [[Coconuts]]
|-
|9 || [[Pelargonic acid]] || Nonanoic acid || {{chem2|CH3(CH2)7COOH}} || [[Pelargonium]] plant
|-
|10 || [[Capric acid]] || Decanoic acid || {{chem2|CH3(CH2)8COOH}} || [[Coconut oil|Coconut]] and [[Palm kernel oil]]
|-
|11 || [[Undecylic acid]] || Undecanoic acid || {{chem2|CH3(CH2)9COOH}} || Anti-fungal agent
|-
|12 || [[Lauric acid]] || Dodecanoic acid || {{chem2|CH3(CH2)10COOH}} || [[Coconut oil]] and hand wash soaps
|-
|13 || [[Tridecylic acid]] || Tridecanoic acid || {{chem2|CH3(CH2)11COOH}} || Plant metabolite
|-
|14 || [[Myristic acid]] || Tetradecanoic acid || {{chem2|CH3(CH2)12COOH}} || [[Nutmeg]]
|-
|15 || [[Pentadecylic acid]] || Pentadecanoic acid || {{chem2|CH3(CH2)13COOH}} || Milk fat
|-
|16 || [[Palmitic acid]] || Hexadecanoic acid || {{chem2|CH3(CH2)14COOH}} || [[Palm oil]]
|-
|17 || [[Margaric acid]] || Heptadecanoic acid || {{chem2|CH3(CH2)15COOH}} || Pheromone in various animals
|-
|18 || [[Stearic acid]] || Octadecanoic acid || {{chem2|CH3(CH2)16COOH}} || [[Chocolate]], waxes, soaps, and oils
|-
|19 || [[Nonadecylic acid]] || Nonadecanoic acid || {{chem2|CH3(CH2)17COOH}} || Fats, vegetable oils, [[pheromone]]
|-
|20 || [[Arachidic acid]] || Icosanoic acid || {{chem2|CH3(CH2)18COOH}} || [[Peanut oil]]
|}

{|class = "wikitable"
|+ Other carboxylic acids
! Compound class
! Members
|-
|unsaturated monocarboxylic acids || [[acrylic acid]] (2-propenoic acid) – {{chem2|CH2\dCH\sCOOH}}, used in polymer synthesis
|-
| [[Fatty acid]]s || medium to long-chain saturated and unsaturated monocarboxylic acids, with even number of carbons; examples: [[docosahexaenoic acid]] and [[eicosapentaenoic acid]] (nutritional supplements)
|-
| [[Amino acid]]s ||the building-blocks of [[protein]]s
|-
| [[Keto acid]]s || acids of biochemical significance that contain a [[ketone]] group; examples: [[acetoacetic acid]] and [[pyruvic acid]]
|-
| [[Aromatic compound|Aromatic]] carboxylic acids || containing at least one aromatic ring; examples: [[benzoic acid]] – the sodium salt of benzoic acid is used as a food preservative; [[salicylic acid]] – a beta-hydroxy type found in many skin-care products; [[phenyl alkanoic acids]] – the class of compounds where a phenyl group is attached to a carboxylic acid
|-
| [[Dicarboxylic acid]]s || containing two carboxyl groups; examples: [[adipic acid]] the monomer used to produce [[nylon]] and [[aldaric acid]] – a family of sugar acids
|-
| [[Tricarboxylic acid]]s || containing three carboxyl groups; examples: [[citric acid]] – found in [[citrus fruit]]s and [[isocitric acid]]
|-
| [[Alpha hydroxy acid]]s || containing a hydroxy group in the first position; examples: [[glyceric acid]], [[glycolic acid]] and [[lactic acid]] (2-hydroxypropanoic acid) – found in sour milk, [[tartaric acid]] – found in wine
|-
| [[Beta hydroxy acid]]s || containing a hydroxy group in the second position
|-
| [[Omega hydroxy acid]]s ||containing a hydroxy group beyond the first or second position
|-
| [[Divinylether fatty acids]] || containing a doubly unsaturated carbon chain attached via an ether bond to a fatty acid, found in some plants
|}