Phosphorus trifluoride appears as a colorless gas and it is extremely toxic in nature comparable to carbon monoxide or equivalent to phosgene. That is odorless, nucleophile, and also weak base in nature and has a chemical formula that PF3.

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In this article, us will discuss Phosphorous trifluoride (PF3) lewis dot structure, molecule geometry, electron geometry, hybridization, polar or nonpolar, its shortcut angle, etc.

“Phosphorus trifluoride is similar to carbon monoxide in the it is a gas i m sorry strongly binding to iron in hemoglobin, staying clear of the blood from absorbing oxygen.”

Properties the Phosphorous trifluoride

It has a molar mass of 87.96 g/mol.It has a boiling suggest of −101.8 °C and also a melting point of −151.5 °C.It has actually a dipole moment of 1.03 D.It is non-flammable gas.It is a very toxic gas and also reacts slowly with water
Name of MoleculePhosphorous trifluoride
Chemical formulaPF3
Molecular geometry/shape of PF3Trigonal pyramid
Electron geometry that PF3Tetrahedral
Bond angle96°
Total Valence electron because that PF326
The formal charge of PF30

Page Contents show
1 just how to draw lewis structure of PF3
2 straightforward steps for illustration the Lewis dot structure for PF3
3 What room the electron and also molecular geometry of PF3?
4 Hybridization of PF3
5 The bond edge of PF3
6 Phosphorous trifluoride polarity: is PF3 polar or nonpolar
7 Three factors that show the polarity the PF3
9 an overview

How to draw lewis framework of PF3

PF3 lewis structure is comprised of one phosphorous atom that situated at the main position and also three fluorine atom that spread around the central atom. There room a complete of 10 lone pairs(including main and terminal atoms) and also three external inspection pairs existing in the lewis dot structure of PF3.

Let’s see exactly how to draw the lewis structure of PF3 by complying with some an easy steps-

Simple measures for illustration the Lewis dot structure for PF3

1. Count full valence electron in PF3

In the an initial step, we have actually to discover how numerous valence electrons room there in PF3, so that we have the right to distribute them around main and terminal atoms v the score of completing their octet shell.

You have two ways to discover out the valence electron for a specific atom, either by spring at their periodic group or by creating their digital configuration. Us will usage the method of the periodic team for finding the valence electron in PF3.

Phosphorous atom belongs come Group 5A or 15A in the routine table, hence, it has actually a 5 valence electron in that is outermost covering whereas fluorine atom belongs to Group 7A or 17A, hence, it has a 7 valence electron in its outermost shell.

⇒ complete valence electron in Phosphorous = 5

⇒ complete valence electron in Fluorine = 7

∴ complete valence electron easily accessible for illustration the PF3 lewis framework = 5 + 7*3 = 26 valence electrons  <∴PF3 has three fluorine atom and one phosphorous>


2. Find the least electronegative atom and also placed it at center

Which is much more electronegative, phosphorous or fluorine atom? that course, the fluorine atom(3.98) is an ext electronegative than phosphorous(2.19). Hence, the fluorine atom goes outside in the lewis diagram conversely, the phosphorus atom fetched the chair of the central position.


3. Connect phosphorous and also fluorine v a single bond

In this step, us start illustration the PF3 skeletal structure by bonding with each other Phosphorous and also Fluorine with a single bond.


Now look at this structure and count how numerous electrons we offered till now and how countless are left. 

As three single bonds are used in the over structure that has 6 electrons and we have a full of 26 valence electron are obtainable for illustration the PF3 lewis structure.

∴ (26 – 6) = 20 valence electrons

So, we are left v 20 valence electrons.

4. Placed remaining valence electrons starting from outer atom first

In this step, we have to place the remaining valence electrons beginning from the an ext electronegative atom or native the outer atoms.

So, fluorine is an ext electronegative than phosphorous and also it requirements 8 electron to finish its octet rule.

Fluorine atoms already sharing 2 electrons with the assist of a single bond so it only requirements 6 an ext electrons to complete its octet rule.


As you view in the over structure, every fluorine has actually 6 electrons stood for as dots and also 2 electrons in type of a single bond, hence, the fluorine atom has a total of 8 electrons and also it perfect its octet comfortably.

Now find how countless valence electrons room left.

Three fluorine atoms in the above structure provided 18 electrons(represented as dots) indigenous a complete of 20 staying valence electrons.

∴ (20 – 18) = 2 valence electrons

So, we left with just 2 electrons.

5. Complete central atom octet and use covalent shortcut if necessary

We space left with just 2 valence electrons and by looking in ~ the 4th step structure, we see, the central atom phosphorus has only 6 electrons(three single bonds), hence, it requirements 2 more electrons to complete the octet and attains stability.

So, put the remaining two electron on the phosphorous atom and complete the octet.


Lewis dot framework for PF3

As you watch in this PF3 lewis dot structure, phosphorous and fluorine completed their octet, and everything watch fine, but, because that the services of satisfaction, us should likewise determine the formal fee in the above structure to know whether the is stable or not.

6. Inspect the security with the assist of a formal charge concept

To calculation the formal charge in the PF3 lewis structure. Use the formula provided below-


Let’s start with the main atom i beg your pardon is phosphorous in the PF3 molecule.

For phosphorous atom:

⇒ Valence electrons of phosphorous = 5

⇒ Lone pair electron on phosphorous = 2

⇒ Bonding electrons of phosphorous(3 solitary bonds) = 6

∴ (5 – 2 – 6/2) = 0 formal fee on the phosphorous central atom.

Each fluorine atom in the PF3 lewis structure has actually the same number of lone pair and also bonded pair electrons, hence, just count formal charge for simply one fluorine atom

 For fluorine atom

⇒ Valence electron of fluorine = 7

⇒ Lone pair electrons on fluorine = 6

⇒ Bonding electrons around fluorine (1 single bond) = 2

∴ (7 – 6 – 2/2) = o formal charge on each fluorine atom.

Hence, each atom in PF3 it s okay a formal fee equal to zero.


Therefore, the above lewis structure of PF3 (phosphorous trifluoride) is the many stable and reliable

The molecular geometry of PF3 is a trigonal pyramid and also its electron geometry is tetrahedral since phosphorous has Sp³ hybridization v 5 valence electron in its valence shell and also it makes three link pairs, one v each fluorine atom.

And one lone pair is current on the central phosphorous atom the tries come repel the bonded bag of electrons, together a result, the surrounding atoms push apart providing its geometry trigonal pyramid.


As you see in the over structure, the lone pair top top the phosphorus atom repel the adjacent electron pairs, as a result, the 2 fluorine atom in equatorial place pushes far apart providing the molecular geometry the PF3 exact same as a trigonal pyramid.

Let’s see how to uncover the molecular and electron geometry of PF3 using the VSEPR chart and also AXN notation.

AXN method is a famous method of identify the molecular and also electron geometry using the VSEPR chart.


AXN notation because that PF3 molecule:

A denotes the central atom, so, in the PF3 molecule, phosphorous is the central atom. A = PhosphorousX denotes the bonded atoms to the central atom, as we know, phosphorous is external inspection with 3 fluorine atoms. Therefore, X = 3N denotes the lone pair top top the main atom, together per PF3 lewis structure, phosphorous has only one lone pair. Hence, N = 1

So, the AXN notation because that the PF3 molecule i do not care AX3N1

As per the VSEPR chart, if a molecule central atom is enclosed with three bonded atoms and has contained only one lone pair ~ above the main atom climate the molecular geometry of the molecule is the trigonal pyramid in nature, and electron geometry is tetrahedral.


Hence, the molecular form for PF3 is a trigonal pyramid and its electron geometry is tetrahedral.


PF3 molecule geometry/shape

Hybridization that PF3

Let’s find the hybridization of PF3 through the steric variety of its main atom.

“Steric number is the enhancement of a total number of bonded atoms around a central atom and also the lone pair current on it.”

∴ Steric variety of PF3 = (Number of bonded atoms attached come phosphorous + Lone pair ~ above phosphorous)

As per the lewis framework of PF3, the main phosphorous atom is external inspection with three fluorine atoms and it includes one lone pair also.

∴ Steric variety of PF3 = (3 + 1) = 4

Steric numberHybridization

So, because that a steric variety of four, we obtain the Sp3 hybridization ~ above a phosphorous atom in the PF3 molecule.

The newly produced hybrid orbitals in PF3 molecule have actually 25% actions of the s orbital and also 75% actions of the p orbital.

The bond angle of PF3

“Phosphorus trifluoride has actually an F−P−F bond angle of approximately 96°“.


PF3 is a polar molecule because of that asymmetric shape and electronegativity difference in between phosphorous and also fluorine which cause non-zero dipole moment.

For knowing, is PF3 polar or non-polar? us will talk about three determinants 1. electronegativity 2. dipole minute 3. Geometrical or molecule shape.

Three determinants that indicate the polarity the PF3 

1. Electronegativity: 

The difference in between the electronegativity the Phosphorous and fluorine is straight proportional to the Polarity of the PF3 molecule.

The electronegativity the the fluorine atom is 3.98 and for the phosphorous atom, its value is 2.19.

So, being much more electronegativity of fluorine help it come attract more bonded electron 보다 phosphorous. Therefore, fluorine gains a partial negative charge, and phosphorous gains a partial hopeful charge.

Positive and negative charges cause non-uniform fee distribution roughly the PF3 structure. Hence, it additionally causes PF3 to come to be polar in nature.

Also, the electronegativity distinction of fluorine and phosphorous atom is greater than 0.5 i beg your pardon ensures the PF3 is very polar in nature follow to the Pauling scale.

2. Dipole moment

The net dipole minute of the PF3 molecule is 1.03 D. Dipole moment measure the toughness of polarity. 

The bigger the electronegativity distinctions of atoms higher is the polarity and also dipole moment.

The dipole that the PF3 molecule originates in the downward and also upward direction since of the lone pair existing in Phosphorous. Hence, it reasons a non-zero dipole minute which causes the polar nature the PF3.

⇒ Dipole moment formula = fee on the atoms * the distance in between them 

∴ D = Q × R

3. Geometrical or molecular shape

The geometrical shape is additionally a huge factor to identify is PF3 polar or non-polar.

As we recognize molecular geometry the PF3 is trigonal pyramidal i beg your pardon is asymmetric and also when the form of the molecule is asymmetric or distorted it doesn’t cancel the dipole moment across the molecule. Hence, reason polar nature of the molecule

All these determinants are sufficient to understand why PF3 is polar in nature.


Why bond edge in PF3 greater than PH3?

This is because, in the PF3 molecule, back bonding occurs.

“The exchange that electrons in between an atomic orbital on one atom and an antibonding orbital on another atom is known as back bonding.”

Due to back bonding, greater bond pair-bond pair repulsion exists in PF3 보다 PH3.

Hence, the higher the repulsion between bonded pairs, the larger is the bond angle.

Also, in the PF3 molecule, fluorine is a highly electronegative atom and it fetched much more electrons towards itself which likewise creates much more repulsion, and this causes, widening the bond edge in PF3. 

The approximate bond angle of PH3 is 93° and also for PF3, that is 96°.

How plenty of lone pairs and bond pairs space present roughly Phosphorous in the PF3 lewis structure?

According to the lewis dot framework of PF3, Phosphorous contains 1 lone pair and also 3 external inspection pair i beg your pardon is enclosed with three fluorine atoms.

How go the PF3 lewis dot framework obey the octet rule?

If an atom gets more or less than 8 electron in one outermost covering then we deserve to say the atom violates the octet.

Phosphorous atom has 5 valence electron in that is outermost shell and it is capable of creating three covalent bonds v the surrounding atom to finish its octet.

Whereas the fluorine atom has actually 7 valence electrons and also is capable of creating only one covalent bond with other atoms.

Therefore, in the PF3 lewis structure, phosphorous as a main atom develops three covalent bonds (one through each fluorine atom) and fulfills that octet requirement whereas the fluorine atom likewise completes its octet through one covalent link attached with the main atom.

∴ every atoms in the PF3 lewis dot structure get exactly 8 electrons in their octet, hence, they space obeying the octet rule

Why is the molecule geometry of PF3 is trigonal pyramid whereas its electron geometry is tetrahedral?

This is due to the fact that there is a slight distinction in molecular and electron geometry. Molecular geometry takes only bonded atoms into account if calculating the shape of any kind of molecule.

Whereas the electron geometry considers both external inspection atoms and also lone bag while predicting the geometry of any kind of molecule.

The phosphorous central has 4 areas of electron density(one lone pair + 3 external inspection pairs) hence, as per VSEPR theory, the electron geometry the PF3 is distorted tetrahedral.

Whereas the molecular geometry that PF3 is trigonal pyramidal that has actually one atom at the center and also three atom at the trigonal base corners and also it is comparable to a tetrahedron but it go not consider lone pair.

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The total valence electron easily accessible for drawing the PF3 lewis framework is 26.The steric variety of the central atoms in phosphorous trifluoride is 4 that ensures that it has actually an Sp3 hybridization.PF3 is polar in nature due to its distorted shape that causes uneven charge distribution all over the atom leads to a non-zero dipole moment and also makes the polar in nature.The molecule geometry or shape for PF3 is the trigonal pyramid.The electron geometry for PF3 is tetrahedral together it central has 4 regions of electron density.Lewis dot framework of PF3 includes 1 lone pair top top the main atom(phosphorous) and also 3 lone bag on each external atom(fluorine).