What is the molecular shape for both #NF_3# and #XeCl_4#?

1 Answer
Jan 29, 2016

Simple VSEPR theory predicts a trigonal pyramid for #NF_3#, and square planar for #XeCl_4#.

Explanation:

The electron pairs, bonding and non-bonding, are arranged around nitrogen in the shape of a tetrahedron. Because we describe molecular geometry on the basis of actual atoms, the geometry of the #NF_3# molecule is trigonal pyramidal.

On the other hand, around the xenon atom there are 4 bonding pairs, i.e. 4 #Xe-Cl# bonds, and 2 lone pairs on Xe. These are arranged in the shape of a octahedron, with the non-bonding electron pairs trans with respect to each other. Because we describe molecular geometry on the basis of actual atoms, the geometry of the #XeCl_4# molecule is square planar.