Lewis Structure of BrO3-

[Madelyn Cearlock]

Can someone please help me with the lewis structure of BrO3-? I don't understand where the double bonds come in.

[Chem_Mod]

Double bonds are necessary to minimize formal charges.

[Grace Kim 1J]

Like the answer above, this structure breaks the octet rule to minimize the formal charges. The total number of valence electrons for BrO3- should be 26. The final structure should have formal charges of 0, except for one of the oxygens (which should be -1). To get the most stable structure, There are double bonds and one single bond attached to Br, along with a lone pair.

[Kayla Vo 1B]

BrO3- has a total of 26 valence electrons. In the Lewis structure, Br is placed in the center since it is lower in electronegativity. With all single bonds connecting the atoms, the formal charge of the O atoms are each -1 while the Br is 2. However, it is best to reduce the formal charges as much as possible since doing so would yield a more stable structure. With double bonds, Br and two O atoms would have a formal charge of 0, thus leaving the remaining O atom with a charge of -1.