What Does Glacial Acetic Acid Mean?
Glacial acetic acid is the anhydrous (undiluted or free of water) form of acetic acid. Acetic acid is considered an organic compound and has the chemical formula CH3COOH.
A diluted solution of acetic acid is known as vinegar or ethanoic acid or ethylic acid. This acid is classified as a weak acid.
Corrosionpedia Explains Glacial Acetic Acid
Glacial acetic acid is a weak colorless reducing agent when it remains free of water (undiluted). This makes it suitable for use in the plastics and food industries. Although a weak acid, it is mildly corrosive to metals such as iron, magnesium and zinc. When reacted with such metals it forms hydrogen gas and salts known as acetates:
Mg + 2 CH3COOH --> (CH3COO)2Mg + H2
Aluminum tanks are used to transport acetic acid because aluminum forms a passivating acid-resistant film of aluminum oxide. Metal acetates can be prepared from acetic acid and an appropriate base, such as the well-known "baking soda plus vinegar" reaction:
NaHCO3 + CH3COOH --> CH3COONa + CO2 + H2O