To draw the Lewis structure for CO (carbon monoxide), follow these steps:
- Determine the total number of valence electrons:
- Carbon (C) has 4 valence electrons.
- Oxygen (O) has 6 valence electrons.
- Total valence electrons = 4 (C) + 6 (O) = 10 electrons.
- Draw the skeletal structure:
- Place the carbon atom (C) and the oxygen atom (O) next to each other.
- Carbon is less electronegative than oxygen, so it will be the central atom.
- Connect the atoms with a single bond:
- Draw a single bond (a line) between the carbon and oxygen atoms. This uses 2 electrons.
- Distribute the remaining electrons:
- You have 8 electrons left (10 total – 2 used in the bond).
- Place 6 electrons around the oxygen atom to complete its octet (3 lone pairs).
- Place the remaining 2 electrons around the carbon atom.
- Check the octet rule:
- Oxygen has 8 electrons (2 in the bond and 6 as lone pairs), satisfying the octet rule.
- Carbon has only 4 electrons (2 in the bond and 2 as lone pairs), which is less than an octet.
- Form a triple bond to satisfy the octet rule:
- Move one lone pair from the oxygen atom to form a triple bond with the carbon atom.
- Now, carbon has 8 electrons (6 in the triple bond and 2 as lone pairs), and oxygen also has 8 electrons (6 in the triple bond and 2 as lone pairs).
The final Lewis structure for CO shows a triple bond between the carbon and oxygen atoms, with each atom having a lone pair of electrons.