Preparation

This acid being volatile may be liberated from any acetate by distilling it with a fixed acid, as sulphuric, but its preparation is now left in the hands of the manufacturers.

Characters And Tests

At the mean temperature of the air, the acid is liquid, but at 34° F. it crystallizes in colorless prismatic crystals, which are not unlike ice, whence the name, glacial. This form is retained up to a temperature of 48° F. The liquid acid has a pungent acetous odor, and is remarkable for the variations in its specific gravity according to its dilution. By the addition of water, the sp. gr. is raised from 1.065 till it reaches 1.073 (corresponding to 84 per cent. of anhydrous acid, C4H1O3), but any further addition of water permanently lowers it.