Formula of glacial acetic acid.

The formula for glacial acetic acid is C2H4O2.

Acetic acid containing a very small amount of water (less than 1%) is called anhydrous (no water) acetic acid or glacial acetic acid. The reason it is called ice cold is because it solidifies into acetic acid crystals that are colder than room temperature at 16.7 ° C, just like ice. Removing water from acetic acid lowers its melting point by 0.2 ° C.

Glacial acetic acid can be obtained by dropping acetic acid over the “stalactite” of solid acetic acid (which can be considered frozen). Pure acetic acid sticks to glacial acetic acid.