Question

In SF4 molecule, the lone pair of electrons occupies an equitorial position rather than axial position in the overall triagonal bipyramidal arrangement. why ?

Answer 1

This arrangement is to avoid the lone pair - bond pair repulsion. If the lone pair occupies the axial position, then there will be three 90 degree lone pair - bond pair repulsion and if it lies in the equatorial position there are only 2 such repulsions which prevents distortion of the molecule.