Carboxylate

Carboxylate ion. The dotted line means there is resonance.

A carboxylate is the conjugate base of a carboxylic acid, R–COO−
(or R–CO−
2). It is an ion with negative charge. Carboxylate ions are made when a carboxylic acid loses a hydrogen ion. Such acids usually have pKa of less than 5, meaning that many bases, such as sodium hydroxide or sodium bicarbonate can remove the hydrogen ions from them.

RCOOH + NaOH → RCOONa + H2O

Examples

Some examples of carboxylates include;

• Formate, HCOO−
  
• Acetate, CH
  3COO−
  
• Oxalate, (COO)2−
  2
• Citrate, C
  3H
  5O(COO)3−
  3

Carboxylate Media

• 

  Acrylate-ion molecule model

• 

  Equivalence of the resonance forms the delocalised form of a general carboxylate anion

• 

  Ester-from-carboxylate-and-alkyl-halide-2D-skeletal

• 

  Reaction of carboxylic acids reduction - part two

• 

  Reaction of carboxylic acids reduction - part three