I HAVE A QUESTION ABOUT AMMONIUM BIFLUORIDE.

The chemical formula for the inorganic substance known as ammonium hydrogen fluoride is either nh4hf2 or nh4fhf. Ammonia and hydrogen fluoride are the two primary ingredients in its production. This odorless salt is used to etch glass and was at one point considered a potential intermediary on the path to producing hydrofluoric acid. 1.structure According to what its name suggests, ammonium bifluoride is composed of a bifluoride, also known as a hydrogen(difluoride) anion: hf2-. This centrosymmetric triatomic anion has the strongest hydrogen bond that is currently known to exist. It has an f-h length of 114 pm. and a bond energy that is larger than 155 kj mol-1. Each ammonium cation in solid [nh4][hf2] is surrounded by four fluoride centers in the shape of a tetrahedron. Hydrogen-fluorine hydrogen bonds are present between the hydrogen atoms of the ammonium ion and the fluorine atoms in the solid. The cations in solutions are of the tetrahedral form (nh4+), whereas the anions are of the linear form (hf2+). 2.the process of manufacturing and its use Some etchants use ammonium bifluoride as one of their ingredients. It has an adverse effect on the silica component of glass: sio2 plus 4 equals nh4 and hf2? sif4 + 4 (nh4f) + 2 water = h2o Another similar etchant that is used more often is potassium bifluoride. Hexafluorosilicic acid is the starting material for the manufacture of hydrofluoric acid, and ammonium bifluoride has been proposed as a possible intermediary in this process. Therefore, hexafluorosilicic acid is hydrolyzed to produce ammonium fluoride, which is then subjected to thermal decomposition, resulting in the production of bifluoride: h2sif6 plus six nh3 plus two h2o? sio2 plus 6 nh4f equals nh4f, right? NH3 with NH4 plus HF2 The ammonium bifluoride that is produced is then changed into sodium bifluoride, which then undergoes thermal decomposition to produce hydrogen fluoride.