Acetic acid, also known as acetic acid, is the most common form of vinegar in daily life (containing acetic acid > 3G / 100ml). The concentration of white vinegar has increased (6g / 100ml ~ 11g / 100ml), and that of acetate (not suitable for consumption) can reach 30g / ml. In addition, apple vinegar beverage also contains acetic acid and a small amount of malic acid (total acid is about 4G / kg, malic acid ≥ 5%).

Pure anhydrous acetic acid is a colorless liquid with pungent smell (sour odor) at room temperature. Its melting point is 16.6 ℃ and boiling point is 117.8 ℃. It is easy to solidify into colorless crystals, so anhydrous acetic acid is also called glacial acetic acid. Acetic acid is easily soluble in water and ethanol, and almost all acetate salts are soluble in water.

Acetic acid is an oxygenated derivative of hydrocarbon, with molecular formula c2h4o2 and structural formula CH3COOH. The nature of acetic acid is mainly determined by its functional group - carboxyl group (picture, or write - COOH).
Acetic acid is a monobasic organic acid, which shows the nature of acid. Its aqueous solution is weakly acidic and corrosive. The pH of acetic acid solution with a concentration of 1mol / L (similar to the concentration of household vinegar) is 3 ~ 4.
CH3COOH ⇌ CH3COO ˉ + H+
It can change the color of the indicator
2CH3COOH+Fe=(CH3COO)2Fe+H2↑
corroding metal
2CH3COOH+CuO=(CH3COO)2Cu+H2O
Insoluble oxide or oxide film is not a problem
2CH3COOH+Cu(OH)2=(CH3COO)2Cu+2H2O
Insoluble alkali can also react
2CH3COOH+CaCO3=(CH3COO)2Ca+CO2↑+H2O
Acidity is greater than carbonic acid