When drawing the best Lewis structure for SCl2, which of the following describes the components around the sulfur atom? 1. There are two double bonds and one lone pair around S. 2. There is one double bond, one single bond, and one lone pair around S. 3. There are two double bonds and no lone pair around S. 4. There are two single bonds and two lone pairs around S. 5. There is one double bond, one single bond, and one lone pair around S
The Correct Answer and Explanation is:
The correct answer is: 4. There are two single bonds and two lone pairs around S.
Explanation:
To determine the best Lewis structure for sulfur dichloride (SCl₂), we must follow standard rules for drawing Lewis structures and consider the valence electrons of each atom.
Step 1: Count the total valence electrons
- Sulfur (S) is in group 16 and has 6 valence electrons.
- Chlorine (Cl) is in group 17 and has 7 valence electrons.
- Since there are two chlorine atoms, they contribute a total of 14 valence electrons.
So, the total number of valence electrons for SCl₂ is:
6 (from sulfur) + 14 (from two chlorine atoms) = 20 valence electrons
Step 2: Draw the skeletal structure
Place sulfur in the center because it is less electronegative than chlorine. Attach each chlorine atom to the sulfur with a single bond. This uses up 4 electrons (2 for each S–Cl bond), leaving 16 electrons.
Step 3: Complete the octets for the chlorine atoms
Each chlorine atom needs 6 more electrons to complete its octet. Adding 6 electrons around each Cl uses up 12 electrons (6 × 2 = 12), leaving 4 electrons.
Step 4: Place remaining electrons on sulfur
The remaining 4 electrons are placed as two lone pairs on the sulfur atom.
Step 5: Confirm octets
- Each chlorine atom has 8 electrons (2 from the bond with sulfur and 6 as lone pairs).
- Sulfur has 8 electrons as well (2 single bonds and 2 lone pairs).
Thus, the correct Lewis structure of SCl₂ shows sulfur forming two single bonds with chlorine atoms and having two lone pairs of electrons. This gives sulfur a total of four electron domains, which results in a bent molecular shape according to VSEPR theory. Therefore, option 4 is the correct description of the components around sulfur.
