What is IOF3 molecular shape?

Answer 1

Where the electron pair is in the structure is important, because every molecule assumes a particular structure because it is lowest in energy ( it conserves the most energy and is more stable relative to other conformations). the "See-saw"structure (where the electron pair occupies an equitorial position) is a lower-energy structure than "trigonal pyramidal"(electron pair occupies an axial position- top or botom) because the electron pair has more electronegativity than the bonded atoms, and therefore occupies the position with the most space from all other substituent atoms (if the electron cloud is in the axial position, all 3 adjacent atoms are 90 degrees from it, where if the electron pair is in an equitorial position, it is 120 degrees from 2 atoms and 90 degrees from the other 2).

Look at the bond angle of hydrogens on NH3 or H2O and you can see how electron pairs actually force other atoms bonded to the central atom closer to each other (the H-N-H bond angle in NH3 is 107.8 degrees and H-O-H bond angle in H2O is 104.5 degrees, whereas 109.5 degrees for tetrahedron molecules, such as CH4 is the case of all atoms are the same (H-C-H)).

For moreinformation, go to: wikipedia's "Molecular geometry" page

Answer 2

Due to the extra set of valence electrons, IOF3 will have a triangular bi-pyramidal shape, with the Oxygen at one terminus and the pair of valence electrons at the other.