Is PF3 Nonpolar or Polar?

Chemical compound PF3 is phosphorus trifluoride, which has the formula PF3. At normal temperature, it exists as an odourless, colourless gas. In nature, it is extremely poisonous. It is possible that many pupils are unsure if PF3 is polar or not. Among other things, we’ll review its qualities and applications in this article.

Polar or Nonpolar: Which is it? The chemical PF3 is polar in nature. The electronegativity of phosphorus and fluorine differs, and the PF3 molecule contains a lone pair as well. Due to the non-zero dipole moment, the form of the molecule is trigonal pyramidal, making it polar.

Trifluorophosphate is an odourless and colourless hazardous chemical. A variety of metal complexes employ it as an important ligand.

The halogenation exchange of various fluoride compounds, such as Xinc fluoride and calcium fluoride, etc., is used to produce phosphorus trifluoride from phosphorus trichloride.

An example of a ZnF2 halogen exchange reaction for the synthesis of PF3 is shown in the graph below.

The reaction is 2PCl3 + 3ZnF2 —-> Phosphorus trifluoride (2 PF3) + ZnCl2 (3 PF3)

The PF3 molecule has one phosphorus atom and three fluorine atoms in its chemical makeup.

Phosphorus contains 5 valence electrons, while fluorine has 7 in its outermost shell.

PF3 has a molecular weight of 3

P = 1 * 30 (mol mass) + 3 * 18.9 (mol mass) = 87.96 g/mol for the molecular mass of PF3.

Three fluorine atoms surround the phosphorus atom in the PF3 molecule. One electron is all that is needed to complete the octet of fluorine.

Consequently, three fluorine atoms form a covalent link with phosphorus, leaving only one lone pair on the phosphorus atom.

Fluorine has an electronegativity of 3.98, while phosphorus has a value of 2.19. The P-F bond is polar because of the difference in electronegativity between the two atoms.

Consequently, all P-F bonds have a non-zero dipole moment in the same direction as a result of this arrangement.

Because of the repulsion between the lone pair and the bond pairs, the bonds on phosphorus atom face a downward repulsive force due to the presence of a lone pair.

As a result, the PF3 molecule has a nonzero dipole moment, making it polar.

What is the difference between polar and nonpolar atoms?

The interatomic forces hold the molecules in place. There were four different types of forces at work here: covalent, ionic, metallic, and hydrogen-bonding interactions.

The strongest bond forces are found in covalent and ionic bonding. Covalent bonds bind polar molecules.

Covalent bonds can be either polar or nonpolar based on the electronegativity, geometrical form, and molecular dipole of the substance they are attached to.

There are molecules that have dipole moments that are greater than zero.

The atoms in these molecules are charged in an unbalanced manner. As previously stated, this is due to the electronegativity differences between the constituents of polar molecules.

If two atoms have different electronegativity, the covalent bond they form is polar.

The bonded charge is drawn toward the more electronegative atom, which obtains a small negative charge in the process.

In the process, another atom gets a partial positive charge, resulting in the formation of two electric poles in the molecule.

H2O and OF2 are two examples of these molecules. You can find out why OF2 is polarised.

As the name suggests, these compounds are nonpolar. The atoms in these molecules are all charged equally.

A nonpolar bond is produced when the charges of the two atoms in a covalent bond are equal.

There is equal influence on the electron pair from both atoms. The molecule does not have any poles.

Br2 and Hexane are two examples of these compounds. The explanation for hexane’s non-polarity can be investigated.

What makes PF3 so polar?

The phosphorus trifluoride molecule is made up of three extremely electronegative fluorine atoms surrounding a core phosphorus atom.

For the octet to be complete, all three fluorine atoms must share one phosphorus electron pair.

Asymmetric P-F bonds are formed as a result of the repulsion between lone pairs and bond pairs, according to VSEPR theory.

The resulting PF3 molecule has a trigonal pyramidal geometrical shape. The dipole moment of all P-F bonds is nonzero.

Approximately 96.3 degrees is the bond angle of (FPF).

Phosphorus trifluoride is a polar compound due to the difference in electronegativity between the P and F atoms and the trigonal pyramidal form of the molecules.

A molecule’s ability to be polarised by external factors

If an atom has high electronegativity, it will attract the electron-bonded pair toward it.

Atoms with higher electronegative potentials have an even stronger pull on the bound electron pair than do those with lower potentials.

Molecular polarity increases when there is a variation in the electronegativity of atoms in the compound.

Molecular polarity is proportional to the electronegativity difference between the atoms that make up the molecule.

Molecules with a symmetrical geometrical structure have no dipole moment. To put it another way, it signifies that nonpolar molecules are found in nature and polar molecules in nature.

Atoms with the same electronegativity and no lone pairs in their molecules generate symmetrical shapes.

Phosphorus trifluoride’s geometric structure can be seen in the figure below.

Note: Symmetrical nonpolar molecules can have polar bonds, but the polarity of the bonds is cancelled out by the symmetry of the geometrical shape, resulting in a nonpolar molecule.

A molecule’s polarity can be determined by measuring its dipole moment. The dipole moment of a molecule determines its polarity.

It is the sum of the atoms’ charges and the distance between them, in terms of math.

D is the product of Q and R

Debye is the abbreviation for the unit’s SI name.

In the metric system, PF3 is a 1.03 D value.

PF3’s Characteristics

At room temperature, phosphorus trifluoride is colourless and odourless.

This substance has a gaseous density of 3.91 g/L.

This compound has a melting point of 151.5 °C (240.7 °F) and a boiling point of 101.8 °C (151.2 °F).

Slow hydrolysis occurs as the chemical becomes water soluble.

Aspects of PF3

This chemical is commonly utilised as a ligand in various metal complexes.

Metal carbonyls use it as ligand, same as CO does.

Conclusion

When three fluorines are covalently bound together, there is one single pair of fluorine on the third fluoride, which is Phosphorus trifluoride.

Since the electronegativity of P and F are different, the P-F bond is polar, according to VSEPR theory, which describes its geometric structure as trigonal pyramidal.

Non-zero dipole moment is guaranteed by the entire molecule.

The PF3 is hence polar.

PF3’s non-polarity can be discussed in the comments section, so feel free to do so! As soon as we can, we’ll get back to you.

Read more: Is HCl a polar or nonpolar substance?

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.

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