Bromite (BrO2)- Ion Lewis Structure
Bromite ion (BrO2)-) is an anion and contains bromine and oxygen atoms. Lewis structure of BrO2)-) contains one Br-O bond and one Br=O bond. Bromine atom has two lone pairs and oxygen atom holds -1 charge. In this tutorial, we will learn how to draw lewis structures of BrO2)- ion.
BrO2 ion lewis structure
There is a single bond between center bromine atom and one oxygen atom. As well, a double is located between same bromine atom and other oxygen atom.
Bromine atom has two lone pairs and one oxygen atom also has two lone pairs. Other oxygen atom has three lone pairs and holds a -1 charge.
Steps of drawing lewis structure of BrO2-
When we draw a lewis structure, guidelines are given for convenience. Number of steps can be changed according the complexity of the molecule or ion. Because Br2 is an ion, there are several steps to draw the lewis structure carefully. However those all steps are mentioned and explained in detail in this tutorial for your knowledge improvement.
- Find total number of electrons of the valance shells of bromine and oxygen atoms
- Total electrons pairs existing as lone pairs and bonds
- Determine center atom
- Mark lone pairs on atoms
- Mark charges on atoms if there are charges.
- Check the stability and minimize charges on atoms by converting lone pairs to bonds to obtain best lewis structure.
Total number of electrons of the valance shells of Br2
There are only two elements in bromite ion. Oxygen, a VIA group element has six electrons in its last shell. Bromine is a group VIIA element in the periodic table and contains seven electrons in its last shell. Now, we know how many electrons are there in valence shells of bromine and oxygen atoms.
- valence electrons given by bromine atoms = 7 * 1 = 7
- valence electrons given by oxygen atoms = 6 * 2 = 12
- Due to -1 charge, number of extra added electrons = 1
- Total valence electrons = 7 + 12 +1
- Total valence electrons = 20
Total valence electrons pairs
Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells
Total electron pairs are determined by dividing the number total valence electrons by two. For, bromite ion, Total pairs of electrons are ten in their valence shells.
Center atom of BrO2- ion
- Fact 1: Because, bromine atom can show higher valence than oxygen atom, bromine atom should be the center atom.
- Fact 2: As well as, because bromine is more electropositive than oxygen, again bromine should be the center atom.
- From above two facts, it is decided that bromine is the center atom in BrO2- ion
Lone pairs on atoms
After determining the center atom and sketch of BrO2- ion, we can start to mark lone pairs on atoms. Remember that, there are total of ten electron pairs.
- There is already two bonds in the drawn skeletal. So, there are eight remaining lone pairs to mark on atoms.
- Start to mark remaining lone pairs on outside atoms (in this case: oxygen atoms). Each oxygen atom will take three lone pairs. So, six electron pairs are marked on oxygen atoms as lone pairs.
- Now, two more valence electrons pairs are remaining and they are marked on bromine atom.
Mark charges on atoms
There are charges above drawn structure as below (each oxygen atom has -1 charge and bromine atom has +1 charge).
Check the stability and minimize charges on atoms by converting lone pairs to bonds
Because, there are charges on every atoms in above structure, that structure is not stable. Therefore, convert lone pairs to bonds as appropriate as below to reduce charges to get the most stable structure.
Questions