Problem 4.9

[Lily Emerson 1I]

Why is the shape of ICl3 T-shaped instead of trigonal planar or trigonal pyramidal?

[Yadira Flores 1G]

The 2 lone pairs on the I in the lewis structure does not allow for the shape to correspond to trigonal planar nor trigonal pyramidal. The VSEPR formula of AX3E2 corresponds to the t-shape.

[jessicasam]

If you draw the lewis structure, you will see that I forms 1 bond with each Cl atom. After giving each Cl a full octet, there are still 4 electrons that are left over. Two lone pairs are added to I because it can have more than an octet. The lewis structure will now have 3 bonds and 2 lone pairs around the central atom. This configuration is T-shaped.

[Faisal Alshamaa - 1L]

Trigonal pyramidal takes on the form of A-X3-E, with 3 atoms bonded to a central atom and a lone pair of the central atom.
ICl3, when you draw the lewis structure, has 2 lone pairs and 3 atoms bonded to the central atom, which takes on the form of A-X3-E2, which is T-Shaped.