Hydrofluoric Acid: A Weak Acid – Yet It Dissolves Glass?
On the far right side of the Periodic Table of the Elements is listed the halogens, which include fluorine, chlorine, bromine, iodine, and astatine. In order of ascending atomic weight we have: fluorine and chlorine gases, bromine liquid, and iodine and astatine solids. Each exhibits a –1 valence. Each attaches to a single atom of hydrogen to form an anhydrous acid. Most of these acids are considered very strong with the exception of hydrofluoric acid. It is comparably a relatively weak acid. This is the case, even though hydrofluoric is the only acid stored in polyethylene bottles because it dissolves glass. Since it can eat its way through glass, how can hydrofluoric acid be considered a weak acid? Hydrofluoric Acid Attacks Glass While hydrofluoric acid is usually written HF, for…