To draw the Lewis dot structure for CS₂ (carbon disulfide), follow these steps:
- Determine the total number of valence electrons:
- Carbon (C) has 4 valence electrons.
- Sulfur (S) has 6 valence electrons.
- Since there are two sulfur atoms, the total number of valence electrons is 4 (from carbon) + 6 (from sulfur) × 2 = 16 electrons.
- Identify the central atom:
- Carbon is the central atom because it is less electronegative than sulfur.
- Draw the skeletal structure:
- Place the carbon atom in the center and the two sulfur atoms on either side.
- Distribute the electrons:
- Start by placing a single bond between the carbon and each sulfur atom. This uses 4 electrons (2 bonds × 2 electrons each).
- Distribute the remaining 12 electrons as lone pairs on the sulfur atoms. Each sulfur atom will have 3 lone pairs (6 electrons).
- Check the octet rule:
- Carbon has 4 electrons (2 from each bond), satisfying the octet rule.
- Each sulfur atom has 8 electrons (2 from the bond and 6 from lone pairs), also satisfying the octet rule.
The final Lewis dot structure for CS₂ looks like this:
S = C = S
In this structure, the carbon atom is double-bonded to each sulfur atom, and each sulfur atom has three lone pairs of electrons.