Inorganic Chemistry

Question

(A) Only one of the chemicals listed below is stable under normal laboratory conditions (e.g. normal Temperature, Pressure and atmosphere). Use your knowledge of Oxidation States and/or VSEPR and/or trends in reactivity to select the stable compound and state why each of the others cannot normally exist as written.

(i)               SO₅

(ii)             MgF

(iii)           RbF

(iv)           BF₃

(v)             SbF₂

(vi)           Tetrahedral SF₄

Answer 1

The first pass should be to eliminate compounds that don't fit the valence (or oxidation states) of the two elements:

SO₅ , MgF, SF₄ , SbF₂

SF₄ exists and is a "see-saw shape" . The tetrahedral version is not stable (tetra would be something like SiF₄)

BF₃ is usually the model molecule for the trigonal planar shape. It is reactive, but I wouldn't say unstable.

RbF is the correct formula for rubidium fluoride, a solid salt. I would go with that.

Please consider a tutor.