Answer to Question #142290 in Inorganic Chemistry for Sarita bartwal

Question

Explain the structure on the basis of VSEPR theory a) SF4

Answer 1

The molecular geometry for sulfur tetrafluoride (SF₄) with 34 valence electrons can be explained on the basis of VSEPR. The VSEPR model predicts the trigonal bipyramidal electron-group geometry. However, because one of the electron groups is a lone pair, the molecular geometry is not a trigonal bipyramid. Because the lone pair requires more space than the bonding pairs of electrons when we are using the VSEPR model, the lone pair will occupy the position with the fewest repulsions. In the trigonal bipyramid, the most unhindered site is one of the equatorial positions. In fact, lone pairs in trigonal bypyramids will always occupy the equatorial positions. The space-eating lone pairs then push against the other electron pairs and distort them from their ideal bond angles. The result for SF₄ is referred to as a seesaw structure.