Construct the Lewis Structure Model for the Covalent Compound Phosgene (COCl2)

To construct the Lewis structure for phosgene (COCl₂), follow these simple steps:

1. Determine the total number of valence electrons: For COCl₂, we need to consider the valence electrons from each atom. Carbon (C) has 4 valence electrons, Oxygen (O) has 6, and each Chlorine (Cl) has 7. Therefore, the total is:
• 1 C = 4 electrons
• 1 O = 6 electrons
• 2 Cl = 7 * 2 = 14 electrons

Total = 4 + 6 + 14 = 24 valence electrons.

2. Identify the central atom: In COCl₂, carbon (C) is the central atom since it can form four bonds compared to oxygen and chlorine.
3. Add electron pairs to show the bonds: Start by placing carbon in the center, and bond it to the oxygen atom and the two chlorine atoms. Each bond consists of a pair of electrons. This will use 6 of our 24 total electrons. After bonding:
• C-O = 1 bond (2 electrons)
• C-Cl = 1 bond (2 electrons)
• C-Cl = 1 bond (2 electrons)

Now we have used 6 electrons, leaving us with 18 valence electrons.

4. Complete the octets for the surrounding atoms: Each chlorine needs 8 electrons, and oxygen also needs 8 electrons. Start by adding lone pairs:
• Each Cl has 3 lone pairs (6 electrons).
• O has 2 lone pairs (4 electrons).

The two chlorine atoms take 6 electrons each (3 pairs) and the oxygen takes 4 electrons (2 pairs). This completes each atom’s octet while utilizing all 24 valence electrons.

The final Lewis structure for phosgene (COCl₂) looks like this:

    Cl
    : 
    C = O
    : 
    Cl

This representation shows that carbon is the central atom, bonded to an oxygen atom with a double bond and two chlorine atoms with single bonds, fulfilling the octet rule for all atoms involved.