To draw the Lewis structure for OCl2 (dichlorine monoxide), we need to follow a few steps to ensure we represent the molecule accurately.
- Count the Valence Electrons:
The first step is to count the total number of valence electrons. Oxygen (O) has 6 valence electrons, and each chlorine (Cl) atom has 7 valence electrons. Therefore, we have:
- O: 6
- Cl: 7 x 2 = 14
Total = 6 + 14 = 20 valence electrons.
- Determine the Central Atom:
Oxygen is less electronegative than chlorine, so it will be the central atom. The structure will be O in the center with two Cl atoms bonded to it.
- Draw the Skeletal Structure:
We place the chlorine atoms on either side of the oxygen, like this:
Cl – O – Cl
- Add Bonds:
Next, we connect the oxygen to each chlorine with a single bond, which uses up 4 valence electrons (2 for each bond).
- Calculate Remaining Electrons:
After forming the bonds (4 electrons used), we have:
20 – 4 = 16 valence electrons remaining.
- Distribute Remaining Electrons:
We need to fulfill the octet rule for each atom. We start by placing 6 electrons (3 lone pairs) around each chlorine atom, which accounts for 12 electrons:
Cl: 3 lone pairs
Cl: 3 lone pairs
- Place Leftover Electrons on Central Atom:
Now, we have used 16 electrons (4 for the bonds and 12 for the chlorines), leaving us with 0 electrons. We will place 2 of the remaining electrons as a lone pair on the oxygen:
Thus, the final Lewis structure will look like this:
..
:
Cl - O - Cl
:
..
In this structure, each chlorine atom has 8 electrons (6 from lone pairs and 2 from the bond with oxygen), fulfilling the octet rule. The oxygen atom has 8 electrons as well (6 from the lone pair and 2 from the bonds with chlorine), also satisfying the octet rule.
This Lewis structure shows that dichlorine monoxide has a central oxygen atom bonded to two chlorine atoms, with the oxygen bearing a lone pair of electrons, resulting in a bent molecular shape.