Acetate ion (CH₃COO⁻)
- Charge
- −1
- Atoms
- C × 2, H × 3, O × 2
- Atoms in total
- 7
- Mass of the ion
- 59.044 g/mol
Acetate is what remains when acetic acid, the acid in vinegar, gives up the hydrogen ion from its COOH group. It contains two carbon, three hydrogen and two oxygen atoms, and the electron left behind gives it a 1− charge shared between the two oxygens. You meet it in salt-and-vinegar flavorings, food preservatives and reusable hand warmers filled with sodium acetate.
- Acids whose names end in -ic give ions ending in -ate, so acetic acid gives acetate, just as carbonic acid gives carbonate.
- The same ion is also written C₂H₃O₂⁻ or shortened to OAc⁻, and all three describe the same group of atoms.
- Sodium acetate, CH₃COONa, crystallizes suddenly from a supersaturated solution and releases heat, which is how clicker hand warmers work.
Compounds that contain acetate
CH3COONa Sodium acetate
CH3COOK Potassium acetate
Ca(CH3COO)2 Calcium acetate
CH3COONH4 Ammonium acetate