Lewis Structure of HF (With 6 Simple Steps to Draw!)

I’m super excited to teach you the lewis structure of HF in just 6 simple steps.

Infact, I’ve also given the step-by-step images for drawing the lewis dot structure of HF molecule.

So, if you are ready to go with these 6 simple steps, then let’s dive right into it!

Lewis structure of HF (or Hydrogen fluoride) contains one single bond between the Hydrogen (H) and Fluorine (F) atom. The Fluorine atom has 3 lone pairs.

Let’s draw and understand this lewis dot structure step by step.

(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of HF).

6 Steps to Draw the Lewis Structure of HF

Step #1: Calculate the total number of valence electrons

Here, the given molecule is HF (hydrogen fluorine). In order to draw the lewis structure of HF, first of all you have to find the total number of valence electrons present in the HF molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).

So, let’s calculate this first.

Calculation of valence electrons in HF

For Hydrogen:

Hydrogen is a group 1 element on the periodic table. ^[1]

Hence, the valence electron present in hydrogen is 1 (see below image).

For Fluorine:

Fluorine is a group 17 element on the periodic table. ^[2]

Hence, the valence electrons present in fluorine is 7 (see below image).

Hence in a HF molecule,

Valence electrons given by Fluorine (F) atom = 7
Valence electron given by each Hydrogen (H) atom = 1
So, total number of Valence electrons in HF molecule = 1 + 7 = 8

Step #2: Select the center atom (H is always outside)

While selecting the atom, you have to put the least electronegative atom at the center.

But here in the HF molecule, there are only two atoms. So you can consider any of the atoms as a center atom.

So, let’s assume that the Fluorine atom is a central atom. (Because hydrogen is always placed outside in any lewis structure.)

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of HF molecule, put the two electrons (i.e electron pair) between fluorine and hydrogen atom to represent a chemical bond between them.

These pair of electrons present between the Fluorine (F) and Hydrogen (H) atoms form a chemical bond, which bonds the fluorine and hydrogen atoms with each other in a HF molecule.

Step #4: Complete the octet (or duplet) on outside atoms. If the valence electrons are left, then put the valence electrons pair on the central atom

Don’t worry, I’ll explain!

In the Lewis structure of HF, the outer atom is hydrogen atom.

So now, you have to check whether this hydrogen atom is forming a duplet or not! (because hydrogen requires only 2 electrons to have a complete outer shell).

You can see in the above image that the hydrogen atom forms a duplet.

Also, only 2 valence electrons of HF molecule are used in the above structure.

But there are total 8 valence electrons in HF molecule (as calculated in step #1).

So the number of electrons left to be kept on the atom (i.e fluorine atom) = 8 – 2 = 6.

So let’s keep these six electrons (i.e 3 electron pairs) on the fluorine atom.

Now, let’s move to the next step.

Step #5: Check whether the central atom has octet or not

In this step, we have to check whether the central atom (i.e fluorine) has an octet or not.

In simple words, we have to check whether the central Fluorine (F) atom is having 8 electrons or not.

As you can see from the above image, the central atom (i.e fluorine), is having 8 electrons. So it fulfills the octet rule and the fluorine atom is stable.

Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom

Now, you have come to the final step and here you have to check the formal charge on fluorine atom (F) as well as hydrogen atom (H).

For that, you need to remember the formula of formal charge;

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

For Fluorine:
Valence electrons = 7 (as it is in group 17)
Nonbonding electrons = 6
Bonding electrons = 2
For Hydrogen:
Valence electron = 1 (as it is in group 1)
Nonbonding electrons = 0
Bonding electrons = 2

Formal charge	=	Valence electrons	–	Nonbonding electrons	–	(Bonding electrons)/2
F	=	7	–	6	–	2/2	=	0
H	=	1	–	0	–	2/2	=	0

So you can see above that the formal charges on fluorine as well as hydrogen are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of HF is the final stable structure only.

Each electron pair (:) in the lewis dot structure of HF represents the single bond ( | ). So the above lewis dot structure of HF can also be represented as shown below.

Article by;

Jay Rana

Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. With a desire to make learning accessible for everyone, he founded Knords Learning, an online learning platform that provides students with easily understandable explanations. Read more about our Editorial process.

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