Lewis Structure of PF3Cl2 (With 5 Simple Steps to Draw!)

Ready to learn how to draw the lewis structure of PF3Cl2?

Awesome!

Here, I have explained 5 simple steps to draw the lewis dot structure of PF3Cl2 (along with images).

So, if you are ready to go with these 5 simple steps, then let’s dive right into it!

Lewis structure of PF3Cl2 contains a single bond between the Phosphorus-Chlorine atoms and Phosphorus-Fluorine atoms. The Phosphorus atom (P) is at the center and it is surrounded by 3 Fluorine atoms (F) and 2 Chlorine atoms (Cl). The Phosphorus atom does not have a lone pair while the fluorine & chlorine atoms have three lone pairs each.

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 PF3Cl2).

5 Steps to Draw the Lewis Structure of PF3Cl2

Step #1: Calculate the total number of valence electrons

Here, the given molecule is PF3Cl2. In order to draw the lewis structure of PF3Cl2, first of all you have to find the total number of valence electrons present in the PF3Cl2 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 PF3Cl2

For Phosphorus:

Phosphorus is a group 15 element on the periodic table. ^[1]

Hence, the valence electrons present in phosphorus is 5 (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).

For Chlorine:

Chlorine is a group 17 element on the periodic table. ^[3]

Hence, the valence electron present in chlorine is 7 (see below image).

Hence in a PF3Cl2 molecule,

Valence electrons given by Phosphorus (P) atom = 5
Valence electrons given by each Fluorine (F) atom = 7
Valence electrons given by each Chlorine (Cl) atom = 7
So, total number of Valence electrons in PF3Cl2 molecule = 5 + 7(3) + 7(2) = 40

Step #2: Select the center atom

While selecting the center atom, always put the least electronegative atom at the center.

(Remember: Fluorine is the most electronegative element on the periodic table and the electronegativity decreases as we move right to left in the periodic table as well as top to bottom in the periodic table). ^[4]

Here in the PF3Cl2 molecule, if we compare the phosphorus atom (P), fluorine atom (F) and chlorine atom (Cl), then phosphorus is less electronegative.

So, phosphorus should be placed in the center and the remaining fluorine and chlorine atoms will surround it.

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

Now in the above sketch of PF3Cl2 molecule, put the two electrons (i.e electron pair) between each phosphorus-chlorine and phosphorus-fluorine atoms to represent a chemical bond between them.

These pairs of electrons present between the Phosphorus (P), Chlorine (Cl) and Fluorine (F) atoms form a chemical bond, which bonds these atoms in a PF3Cl2 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 PF3Cl2, the outer atoms are chlorine atoms and fluorine atoms.

So now, you have to complete the octet on these chlorine atoms and fluorine atoms (because chlorine and fluorine requires 8 electrons to have a complete outer shell).

Now, you can see in the above image that all the chlorine and fluorine atoms form an octet.

Also, all the 40 valence electrons of PF3Cl2 molecule (as calculated in step #1) are used in the above structure. So there are no remaining electron pairs.

Hence there is no change in the above sketch of PF3Cl2.

Let’s move to the next step.

Step #5: 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 phosphorus atom (P), fluorine atoms (F) as well as chlorine atoms (Cl).

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

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

For Phosphorus:
Valence electrons = 5 (as it is in group 15)
Nonbonding electrons = 0
Bonding electrons = 10

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

For Chlorine:
Valence electron = 7 (as it is in group 17)
Nonbonding electrons = 6
Bonding electrons = 2

Formal charge	=	Valence electrons	–	Nonbonding electrons	–	(Bonding electrons)/2
P	=	5	–	0	–	10/2	=	0
F	=	7	–	6	–	2/2	=	0
Cl	=	7	–	6	–	2/2	=	0

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

Hence, there will not be any change in the above structure and the above lewis structure of PF3Cl2 is the final stable structure only.

Each electron pair (:) in the lewis dot structure of PF3Cl2 represents the single bond ( | ). So the above lewis dot structure of PF3Cl2 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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