What is the Lewis Dot Structure for #BrO_2^-# and what are the formal charges on each atom?

1 Answer
Aug 13, 2016

We have #7+6+6+1# valence electrons to distribute, i.e. #"10 electron pairs."#

Explanation:

#O=Br-O^-#.

Going from left to right, there are 2 lone pairs on the doubly bound oxygen, 2 lone pairs on Br, and 3 lone pairs on the singly bound oxygen (and since this centre owns 7 electrons, it has a formal negative charge). This distribution of electron pairs about #Br#, bonding and non-bonding, is tetrahedral to a first approx. and the #/_O-Br-O# bond angle should be #104-5""^@#, compressed from the the ideal tetrahedral #/_109.5""^@# by the influence on the non-bonding lone pairs.