OF2 lewis Structure: Drawings, Hybridization, Shape, Charges, Pair And Detailed Facts


In the present article we are going to discuss OF2 lewis structure (Oxygen difluoride) and detailed explanation of its hybridization, shape, charges, pair and detail facts.

The OF2 lewis structure consist of one oxygen atom as the central atom and two fluorine atom are present on the either side of the oxygen atom. The Lewis structure of OF2 molecule contains 16 non-bonding electrons i.e. 8 lone pairs. From the 8 lone pairs, 3 lone pairs are present on the fluorine atom and 2 lone pairs are present on the central atom oxygen.

OF2 molecule details-

Molecular NameOxygen difluoride
Chemical FormulaOF2
Central atom of the lewis structureOxygen
Number of lone pairs on central atom 2
Molecular Geometry of OF2Bent
Electron Geometry of OF2Tetrahedral
Bon Angle F-O-F103 degree
No. of valence electron for OF2 molecule20
The formal charge of oF2 molecule0

How to draw lewis structure for OF2?

Following are the steps to follow to draw the Lewis structure of OF2 molecule

Step 1: Count total valence electrons present in OF2 molecule

First step is to find the no. of valence electrons present in OF2 molecule.

Oxygen belongs to group 16th and fluorine belongs to group 17th of the periodic table.

Valence electron of oxygen = 6

Valence electron of fluorine = 7

                                                     

Valence ElectronsAtom in OF2Total Electrons
O611*6=6
F727*2=14
20
Table: Total Valence Electrons Of OF2 molecule   

Step 2: Find least electronegative element in OF2 molecule

Electronegativity in a period increases from left to right so oxygen is least electronegative than fluorine. Keep the least electronegative atom in the centre.

Now draw the skeletal structure of OF2 molecule

                            F   O   F

Step 2: How to draw Lewis dot Structure

Step 3: Put two electrons or a bond between F and O atom

F : O : F

or     

   F – O – F

step 3 : How to draw Lewis Structure

Step 4: Complete octet of the Outer atoms

Complete the octet on outside atoms then move on to central atom.

Step 5: Complete octet of central atom or make covalent bonds if necessary

Step 6: Check formal charge value

Before we confirm that this is a perfect Lewis structure, we need to check the formal charge values

Formal charge = Valence electrons – (1/2) * bonding electrons – non-          bonding electrons

Valence electrons of oxygen = 6

Non-bonding electrons of Oxygen = 4 (2 lone pairs)

Bonding electrons of Oxygen= 4 (2 pairs)

Formal charge for Oxygen atom = 6 – 1/2*4 – 4 = 0

Valence electrons of fluorine = 7

Non-bonding electrons of fluorine = 6 (3 lone pairs)

Bonding electrons of fluorine = 2

Formal charge for fluorine atom =7 – 1/2*2 – 6 = 0

As the F and O elements have least possible formal charges, we have obtained suitable Lewis structure

OF2 lewis structure

What is the formal charge in OF2 lewis structure and how it is calculated?

Formal charge is the charge present on an atom in a molecule when all the bonding electrons are shared equally or when the electronegativity difference of atoms is ignored.

Formal charge = Valence electrons – (1/2) * bonding electrons – non-bonding electrons

Valence electrons of oxygen = 6

Non-bonding electrons of Oxygen = 4 (2 lone pairs)

Bonding electrons of Oxygen= 4 (2 pairs)

Formal charge for Oxygen atom = 6 – 1/2*4 – 4 = 0

Valence electrons of fluorine = 7

Non-bonding electrons of fluorine = 6 (3 lone pairs)

Bonding electrons of fluorine = 2

Formal charge for fluorine atom =7 – 1/2*2 – 6 = 0

Thus formal charge on oxygen and fluorine atom in OF2 Lewis dot structure is zero.

Does OF2 molecule follow the octet rule?

OF2 contains 20 valence electrons and all the atoms in OF2 complete their octet as can be seen from the Lewis structure of OF2 molecule. This proves that octet rule is followed by the OF2 molecule.

Why is the molecular Geometry of OF2 is bent?

 Valence shell electron pair repulsion theory (VSEPR) takes into account the repulsion forces between lone pair – lone pair, lone pair – bond pair and bond pair – bond pair and in this way balancing the stability of molecule.

The bent molecular geometry of OF2 molecule is because of the presence of 2 lone pairs on the central oxygen atom. The presence of lone pairs on oxygen atom produces repulsion with electrons of bonded pairs. Due to repulsive forces, fluorine which are present as outer atoms pushes down so as to minimize the repulsion as per the VSEPR theory.

As molecular geometry considers only the atoms present in the molecule so the Molecular Geometry of OF2 molecule is bent.

What is the Electron Geometry of OF2 molecule?

As the electron geometry considers all the electrons as well as lone pairs to determine shape so Electron Geometry of OF2 molecule is tetrahedral.

How to find the molecular shape and electron geometry of OF2 molecule?

In order to find the geometry (molecular/electron) of OF2 molecule, the three steps have to be followed. They are –

1)Find the number of lone pairs present on the central atom in the Lewis structure of OF2 molecule

                Or

Number of lone pairs can also be found by using the formula

Lone Pair =1/2*(V.E. –N.A.)

V.E.= valence electron on the central atom

N.A.= Number of atoms attached to that central atom

In OF2 molecule, the valence electrons of  central oxygen atom is 6 and two outer atoms are attached to it.

Lone Pairs = 1/2* (6 – 2) = 2

2) Find the hybridization number of OF2 molecule

Hybridization of central atom can be found out by using the formula.

Hybridization number = N.A. + L.P

 Where N.A.= number of atoms attached to the central atom

L.P. = number of lone pairs on the central atom

There are two atoms attached to the central atom oxygen and  there are two lone pairs present on it.

 Hybridization number = 2+2 = 4

Hybridization number of OF2 molecule is 4

So hybridization of OF2 molecule is Sp3

3) Use VSEPR Theory to determine OF2 molecular/electron geometry

We have determined hybridization of OF2 as SP3 and lone pairs 2

Now according to AXnEx notation of VSEPR theory we are going to find VSEPR notation for OF2 molecule

AXnEx notation

Where,

 A: central atom

  X: number of atoms attached to the central atom

  E: number of lone pairs of electrons on the central atom

As per Lewis dot structure of Oxygen difluoride, Oxygen is the central atom which has 2 lone pairs of electrons and 2 fluorine atoms are connected to it.

So OF2 formula becomes AX2N2

According to VSEPR chart, the molecule with AX2N2 formula has molecular shape as bent and electron geometry tetrahedral.

Total DomainsGeneral FormulaBonded atomsLone PairsMolecular ShapeElectron Geometry
1AX10LinearLinear
2AX220LinearLinear
 AXE11LinearLinear
3AX330Trigonal PlanarTrigonal Planar
 AX2E21BentTrigonal Planar
 AXE212LinearTrigonal Planar
4AX440TetrahedralTetrahedral
 AX3E31Trigonal PyramidTetrahedral
 AX2E222BentTetrahedral
 AXE313LinearTetrahedral
VSEPR Chart

                      

Why do Bond Angle of OF2 is less than the normal Value?

The Bond Angle OF2 is 103 degrees as the two lone pairs present on the Oxygen molecule decreases the value of bond angle from the normal value. Due to repulsion between the lone pairs, bond angle is 103 degrees.

The bond length of the O-F bond is 140.5pm

Is OF2 molecule polar or non-polar?

OF2 is a polar molecule is confirmed by three factors

1)Electronegativity:

 Fluorine (electronegativity 4) is more electronegative than oxygen (electronegativity 3.5) Being more electronegative than oxygen, fluorine attracts electrons towards it more strongly.

 The molecule is said to be polar If the electronegativity difference between the atoms in the molecule is greater than 0.4

The difference between the electronegativities of Oxygen and fluorine is 0.5.

2)Geometrical/Molecular Shape: 

Shape of OF2 molecule is bent.

The two dipoles – negative charge on fluorine atom and positive charge on the oxygen atom cannot be cancelled because of the bent molecular shape of OF2.

3) Dipole Moment:

The dipole moment exists in OF2 molecule due to polarity of O-F bond. This dipole moment will be towards the more electronegative fluorine atom, as the fluorine atom tries to pull the electron towards it

The bent shape of OF2 molecule is due to the presence of 2 lone pairs of electrons on the central oxygen atom. Due to the bent shape both these dipole moments are not cancelled instead they are sum up, making OF2 a polar molecule.

All these factors show that OF2 is a polar molecule.

The central atom oxygen atom shares two electrons with both fluorine atom. Hence in the Lewis structure there is a presence of two bonding pairs of electrons on the oxygen atom and two non-bonding pairs i.e. two lone pairs on the oxygen atom in the Lewis structure of OF2 molecule

What is the Hybridisation for OF2 molecule?

To share the electrons with the fluorine atoms, the orbitals of oxygen atom undergo hybridization to accommodate the electrons.

The electronic configuration of oxygen and fluorine in ground state is –

Oxygen in ground state 1S2 2S2 2P4

Fluorine in ground state 1S2 2S2 2P5

Electronic configuration of oxygen after gaining two electrons to fulfil the octet by forming bonds with fluorine-

Oxygen 1S2 2S2 2Px2 2Py2 2Pz2

Steric Number = Number of atoms bonded to central atom + Number of lone pairs of electrons attached to central atom

Steric Number = 2+2 = 4

So, hybridization for the central atom oxygen in OF2 is Sp3

Does OF2 molecule shows resonance?

Oxygen difluoride does not have a double bond so it does not show resonance.

A molecule can have resonance if-

  • The molecule has alternate double and single bonds.
  • The molecule has presence of lone pair in conjugation with the double bond.

Conclusion

The OF2 Lewis structure of contains 4 bonding electrons i.e. two bonding pairs and 16 non- bonding electrons i.e. 8 lone pairs.

  • Oxygen Difluoride is made of one oxygen and two fluorine atoms.
  • To summarize what we have discussed in this article, let’s have a look at what we have learned in this article
  • OF2 is a polar molecule with a dipole moment of 0.3D
  • The molecular geometry of OF2 molecule is bent.
  • The OF2 molecule has tetrahedral as the electron geometry.

Sonali Jham

Hi...Myself Sonali Jham. I have done my Post-Graduate in Chemistry and also completed B. Ed. I am a Teacher and a Dietician by profession. My hobby is reading and painting. Let's connect through LinkedIn-https://www.linkedin.com/in/sonali-jham-5110a4212

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