Formate ion (HCOO⁻)
- Charge
- −1
- Atoms
- H, C, O × 2
- Atoms in total
- 4
- Mass of the ion
- 45.017 g/mol
Formate is the simplest carboxylate ion: one carbon atom bonded to one hydrogen atom and two oxygen atoms, with a 1− charge. It is what remains when formic acid, HCOOH, loses the hydrogen ion from its acid group, leaving an extra electron shared by the two oxygens. Formic acid puts the sting in ant bites and nettles, and formate salts de-ice airport runways and preserve animal feed.
- Formic acid takes its name from formica, the Latin word for ant, and formate follows the usual rule that -ic acids give -ate ions.
- Formate is like acetate, CH₃COO⁻, with a hydrogen atom in place of the CH₃ group.
- Sodium formate, HCOONa, is used in fabric dyeing and as a de-icing salt.
Compounds that contain formate
HCOONa Sodium formate
HCOOK Potassium formate
Ca(HCOO)2 Calcium formate