Draw a valid Lewis structure with one central atom

Consider the molecules below
a. CFO
i, Draw a valid Lewis structure with one central atom.
ii. What is the molecular geometry?
iii. What are the bond angles?
iv. is this molecule polar? If yes, draw dipoles on each polar bond and net dipole
v. Does this molecule have resonance? Briefly explain.

The correct answer and explanation is :

Let’s break down the molecule CFO (carbonyl fluoride),

i. Draw a valid Lewis structure with one central atom:

In CFO, carbon (C) is the central atom, as it can form four bonds. Oxygen (O) and fluorine (F) are attached to it. Here’s how we can draw the Lewis structure:

1. Carbon (C) will be at the center, as it is less electronegative than oxygen (O) and fluorine (F).
2. Oxygen and fluorine will each be single-bonded to carbon.
3. Fluorine will have three lone pairs, while oxygen will have two lone pairs.
4. Since oxygen is more electronegative than carbon, it may form a double bond with carbon, leaving fluorine with a single bond to carbon.

The structure is as follows:

   F
   |
C = O

Where the oxygen has two lone pairs and fluorine has three lone pairs.

ii. Molecular Geometry:

The geometry of CFO can be determined by looking at the central carbon atom and its attached atoms.

• Carbon has two regions of electron density (one from the double bond with oxygen and one from the single bond with fluorine).
• Therefore, the molecular geometry will be linear, as two bonding regions around a central atom give a 180° bond angle.

iii. Bond Angles:

The bond angles in a linear molecule are 180°. This is typical for molecules with two atoms bonded to a central atom and no lone pairs.

iv. Is this molecule polar?

Yes, CFO is a polar molecule. Here’s why:

• The C-O bond is polar because oxygen is more electronegative than carbon, so there is a dipole moment from carbon to oxygen.
• The C-F bond is also polar because fluorine is more electronegative than carbon, so the dipole moment is directed from carbon to fluorine.

Given the linear shape of the molecule, the dipole moments do not cancel out, resulting in a net dipole pointing from the carbon atom toward the fluorine.

The individual dipoles on the bonds are shown as:

   δ+   δ-
   F ← C = O → δ-

The overall net dipole is directed toward the fluorine, as fluorine is the most electronegative element.

v. Does this molecule have resonance?

No, CFO does not have resonance. The structure of CFO involves a carbon-oxygen double bond and a single carbon-fluorine bond. Since there is no way to rearrange electrons that would create an alternative structure without breaking octet rules or violating other bonding constraints, resonance does not apply in this case. The bonding is fixed between carbon, oxygen, and fluorine.

Conclusion:

• Lewis structure: Carbon in the center, single bond to fluorine, double bond to oxygen.
• Geometry: Linear.
• Bond angles: 180°.
• Polarity: Yes, polar due to the unequal distribution of electron density.
• Resonance: No resonance.