To determine the formal charges of each atom in the [tex]$\ddot{O}=C=\ddot{O}$[/tex] structure, you'll follow a systematic process. The formal charge (FC) of an atom in a molecule is given by the formula:
[tex]\[ \text{Formal charge} = \text{Valence electrons} - \text{Non-bonding electrons} - \frac{\text{Bonding electrons}}{2} \][/tex]
Let's apply this formula to each atom in the structure:
1. Leftmost Oxygen (O):
- Valence electrons (from the periodic table): Oxygen has 6 valence electrons.
- Non-bonding electrons: Oxygen has 2 lone pairs (4 electrons) in this structure.
- Bonding electrons: Oxygen forms a double bond with Carbon, contributing 4 electrons to the bonding.
Formal charge calculation for the leftmost Oxygen:
[tex]\[
6 - 4 - \frac{4}{2} = 6 - 4 - 2 = 0
\][/tex]
The formal charge on the leftmost Oxygen is 0.
2. Central Carbon (C):
- Valence electrons: Carbon has 4 valence electrons.
- Non-bonding electrons: Carbon has no lone pairs (0 electrons).
- Bonding electrons: Carbon forms two double bonds with Oxygen, contributing 8 electrons to the bonding.
Formal charge calculation for Carbon:
[tex]\[
4 - 0 - \frac{8}{2} = 4 - 0 - 4 = 0
\][/tex]
The formal charge on the central Carbon is 0.
3. Rightmost Oxygen (O):
- Valence electrons: Oxygen has 6 valence electrons.
- Non-bonding electrons: Similar to the leftmost Oxygen, it has 2 lone pairs (4 electrons).
- Bonding electrons: Oxygen forms a double bond with Carbon, contributing 4 electrons to the bonding.
Formal charge calculation for the rightmost Oxygen:
[tex]\[
6 - 4 - \frac{4}{2} = 6 - 4 - 2 = 0
\][/tex]
The formal charge on the rightmost Oxygen is 0.
In summary:
- The formal charge on the leftmost O atom is 0.
- The formal charge on the central C atom is 0.
- The formal charge on the rightmost O atom is 0.
