HOFO Lewis Structure in 6 Steps (With Images)

So you have seen the above image by now, right?

Let me explain the above image in short.

HOFO lewis structure has a Fluorine atom (F) at the center which is surrounded by one Oxygen atom (O) and one O-H group. There is 1 double bond between the Fluorine atom (F) & Oxygen atom (O) and the rest other atoms have a single bond.

If you haven’t understood anything from the above image of HOFO lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of HOFO.

So let’s move to the steps of drawing the lewis structure of HOFO.

Steps of drawing HOFO lewis structure

Step 1: Find the total valence electrons in HOFO molecule

In order to find the total valence electrons in a HOFO molecule, first of all you should know the valence electrons present in hydrogen atom, fluorine atom as well as oxygen atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)

Here, I’ll tell you how you can easily find the valence electrons of hydrogen, fluorine as well as oxygen using a periodic table.

Total valence electrons in HOFO molecule

→ Valence electrons given by hydrogen atom:

Hydrogen is group 1 element on the periodic table. ^[1] Hence the valence electron present in hydrogen is 1.

You can see that only 1 valence electron is present in the hydrogen atom as shown in the above image.

→ Valence electrons given by oxygen atom:

Oxygen is group 16 element on the periodic table. ^[2] Hence the valence electrons present in oxygen is 6.

You can see the 6 valence electrons present in the oxygen atom as shown in the above image.

→ Valence electrons given by fluorine atom:

Fluorine is group 17 element on the periodic table. ^[3] Hence the valence electron present in fluorine is 7.

You can see the 7 valence electrons present in the fluorine atom as shown in the above image.

Hence, 

Total valence electrons in HOFO molecule = valence electrons given by 1 hydrogen atom + valence electrons given by 1 fluorine atom + valence electrons given by 2 oxygen atoms = 1 + 7 + 6(2) = 26.

Step 2: Select the central atom

For selecting the center atom, you have to remember that the atom which is less electronegative remains at the center.

(Remember: If hydrogen is present in the given molecule, then always put hydrogen outside.)

Now here the given molecule is HOFO and it contains hydrogen atom (H), fluorine atom (F) and oxygen atoms (O).

So as per the rule we have to keep hydrogen outside.

Now, you can see the electronegativity values of fluorine atom (F) and oxygen atom (O) in the above periodic table.

If we compare the electronegativity values of fluorine (F) and oxygen (O) then the fluorine atom is less electronegative.

So here the fluorine atom (F) is the center atom and the oxygen atoms (O) are the outside atom.

Step 3: Connect each atoms by putting an electron pair between them

Now in the HOFO molecule, you have to put the electron pairs between the oxygen (O) & hydrogen (H) atom and between the oxygen (O) & fluorine (F) atoms.

This indicates that these atoms are chemically bonded with each other in a HOFO molecule.

Step 4: Make the outer atoms stable

Now in this step, you have to check the stability of the outer atoms.

Here in the sketch of HOFO molecule, you can see that the outer atoms are hydrogen and oxygen atoms.

These hydrogen and oxygen atoms are forming a duplet and octet respectively and hence they are stable.

Also, in step 1 we have calculated the total number of valence electrons present in the HOFO molecule.

The HOFO molecule has a total 20 valence electrons and out of these, only 16 valence electrons are used in the above sketch.

So the number of electrons which are left = 20 – 16 = 4.

You have to put these 4 electrons on the fluorine atoms in the above sketch of HOFO molecule.

Now let’s proceed to the next step.

Step 5: Check the octet on the central atom

In this step, you have to check whether the central fluorine atom (F) is stable or not.

In order to check the stability of the central fluorine (F) atom, we have to check whether it is forming an octet or not.

You can see from the above picture that the fluorine atom is forming an octet. That means it has 8 electrons.

And hence the central fluorine atom is stable.

Now let’s proceed to the final step to check whether the lewis structure of HOFO is stable or not.

Step 6: Check the stability of lewis structure

Now you have come to the final step in which you have to check the stability of lewis structure of HOFO.

The stability of lewis structure can be checked by using a concept of formal charge.

In short, now you have to find the formal charge on hydrogen (H) atom, fluorine (F) atom as well as oxygen (O) atoms present in the HOFO molecule.

For calculating the formal charge, you have to use the following formula;

Formal charge = Valence electrons – (Bonding electrons)/2 – Nonbonding electrons

You can see the number of bonding electrons and nonbonding electrons for each atom of HOFO molecule in the image given below.

For Hydrogen (H) atom:
Valence electron = 1 (because hydrogen is in group 1)
Bonding electrons = 2
Nonbonding electrons = 0

For Fluorine (F) atom:
Valence electrons = 7 (because fluorine is in group 17)
Bonding electrons = 4
Nonbonding electrons = 4

For Oxygen (O) atom:
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 2
Nonbonding electrons = 6

For Oxygen (O) atom (of O-H group):
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 4
Nonbonding electrons = 4

Formal charge	=	Valence electrons	–	(Bonding electrons)/2	–	Nonbonding electrons
H	=	1	–	2/2	–	0	=	0
F	=	7	–	4/2	–	4	=	+1
O	=	6	–	2/2	–	6	=	-1
O (of OH group)	=	6	–	4/2	–	4	=	0

From the above calculations of formal charge, you can see that the fluorine (F) atom has +1 charge and the outer oxygen (O) atom has -1 charge.

Because of this reason, the above obtained lewis structure of HOFO is not stable.

So we have to minimize these charges by shifting the electron pair towards the fluorine atom.

After shifting the electron pairs from oxygen atoms to fluorine atom, the lewis structure of HOFO becomes more stable.

In the above lewis dot structure of HOFO, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of HOFO.

I hope you have completely understood all the above steps.

For more practice and better understanding, you can try other lewis structures listed below.

Try (or at least See) these lewis structures for better understanding:

AlH3 Lewis Structure	MgF2 Lewis Structure
SbF3 Lewis Structure	Cl3- Lewis Structure
PCl2- Lewis Structure	AsO2- Lewis Structure