In the Lewis structure of #ICL_2^-#, how many lone pairs of electrons are around the iodine atom?

1 Answer
Jun 6, 2016

Answer:

Why #"three"#!

Explanation:

For #ICl_2^-#, there are #21+1# valence electrons, i.e. #11# electron pairs to distribute around the three halogens. The iodine atom is presumed to be central, with 2 bonding pairs, and 3 lone pairs. The geometry of electron pairs is presumed to be trigonal bipyramidal, but because we describe the structure based on atoms, not on electron pairs, #ICl_2^-# assumes a linear geometry.

The #I_3^-# ion is also very common. What would you predict as to its geometry? In this representation, where does the negative charge lie?