Cobalt(II) acetate is a salt made by combining cobalt(II) and acetic acid. It is represented by the molecular formula Co(C2H3O2)2 and can be derived from a reaction between CoO, which is cobalt oxide, and HC2H3O2, which is acetic acid. It is sometimes called cobaltous acetate.
As a solid, cobalt(II) acetate appears as a pink crystal or crystalline powder and has a vinegar-like odor. It is used as a catalytic agent in both manufacturing and pharmacology. It is poisonous and flammable when exposed to oxides. In its anhydrous state, cobalt(II) acetate has a molar mass of 177.02 grams per mole. It has a molar mass of 249.08 grams per mole in its tetrahydrate state.