Thionyl chloride (SOCl2 )appears as colourless to yellow fuming liquid, it is soluble in water. It is widely used as a chlorinating reagent in both industrial and scientific applications due to its ability to provide two chlorine atoms.

Steps to draw lewis structure of SOCl2

Step1:Count total valence electron in SOCl2

In the very first step, we will count the total valence electron in the SOCl2 molecule. To find the valence electron, look at the periodic group of the individual atoms – sulfur, oxygen, and chlorine.

The chlorine atom belongs to the periodic group 7A or 17th in the periodic table, hence, the valence electron in the chlorine atom is 7. The oxygen and sulfur atom are situated in the same periodic group which is 6A or 16th in the periodic table.

Hence, the valence electron in both sulfur and oxygen is 6.

? Valence electron in chlorine atom = 7

? Valence electron in oxygen atom = 6

? valence electrons in sulfur = 6

So total valence electron available for drawing the Lewis structure of SOCl2 = 6 + 6 + 7(2) = 26 valence electrons.

Step 2: Determine the central atom

Sulfur atom is the central atom in Thionyl chloride because is the least electronegative atom in the SOCl2 compound.

Step 3: Arrange Electrons Around Atoms

Connect sulfur to oxygen with a double bond (S=O).

Connect sulfur to each chlorine with a single bond (S–Cl).

Each bond consists of 2 electrons.

Step 4:Distribute the remaining electrons

Assign lone pairs to the outer atoms first (O and Cl) to complete their octets:

Oxygen: 2 lone pairs (4 electrons) + 4 electrons in the double bond = 8 total electrons.

Each Chlorine: 3 lone pairs (6 electrons) + 2 electrons in the S–Cl bond = 8 total electrons.

Sulfur, as a third-period element, can have an expanded octet:

Sulfur participates in 1 double bond + 2 single bonds = 10 electrons around it.

Step 5: Check if central atom has complete octet

Check for Formal Charges: Formal charges may not be necessary as all atoms have achieved the octet rule.