Question

Fluorine forms hydrogen dihalides while other hydrogen halides do not form hydrogen dihalides. Give reason.

Answer 1

HF is a stronger acid at high concentration.

At high concentrations, the equilibrium involves the removal of fluoride ions is important, since, it affects the dissociation of hydrogen fluoride and increases the concentration of hydrogen ions. Hence, salts like NaHF₂, KHF₂, NH₄HF₂ are known. The other hydrogen halides do not form hydrogen dihalides.