How Is BF3 NonPolar And Why Not Polar, Detailed Facts


In this article we discuss about how is BF3 Nonpolar in nature and why it is not polar in nature. As a next part, molecular geometry, electron geometry and VSEPR geometry of Boron trifluoride is also elaborated.

Chemical formula of the Boron trifluoride is BF3. BF3 is nonpolar in nature because it is highly symmetric in shape. Vector sum of the dipole moments of three polar bonds of each B-F bond is zero because of the trigonal planar structure of boron trifluoride.

Is BF3 polar?

No, BF3 is not polar molecule but it is non-polar in nature. Each B-F bonds are polar bonds which means that electrons are not shared equally by the Boron and the Fluorine atom but instead of they are pulled towards Fluorine atom.

The electronegative value of Boron and Fluorine is 2.04 and 3.98 respectively. Its electronegative difference between Boron and Fluorine is 1.94. Due to the large electronegative value of Fluorine it pull the shared electrons towards itself by creating a partial negative charge (δ-) on Fluorine atom and Boron will have a partial positive charge (δ+).

Polarity Boron trifluoride
Polarity of Boron trifluoride from wikimedia commons

Three B-F bonds are evenly spaced and their bond angle is 120 degrees. BF3 molecule has planar trigonal structure therefore net dipole in that plane is cancelled and their resultant dipole moment is zero.

BF3 Molecular Geometry:

Geometry of the boron trifluoride is trigonal planar. Each B-F bonds are all evenly spaced 120 degrees apart, such that each of them makes an equilateral triangle therefore their bond angle is 120 degrees.

Boron is the central atom attached to the three fluorine atoms which exhibits trigonal planar geometry. Here, three fluorine atom are wrapped around one Boron center atom and forms trigonal planar which is similar to the peripheral atoms exist in one plane in Boron trifluoride.

Trigonal planar geometry of BF3
Trigonal planar geometry of Boron trifluoride

BF3 Electron Geometry:

It is possible to calculate the electron geometry of Boron trifluoride with the help of bonded pair and lone pair of electron. Since there is no lone pair of electron present in the central boron atom therefore electron geometry and molecular geometry of BF3 is same. Therefore electron geometry of boron trifluoride is trigonal planar.

Electron geometry of Boron trifluoride is the arrangement of electron pairs that is bonding and lone pair of the electrons around a central boron atom to determine the geometry of the molecule. But in case of molecular geometry, we consider only the bond pair of electron.

Electron geometry of Boron trifluoride
Electron geometry of Boron trifluoride from wikimedia commons

BF3 VSEPR Geometry:

BF3 has three electron pairs, from VSEPR chart the structure of the molecule is trigonal planar molecular geometry. Its bond angles is 120 °, they are arranged in such a manner that each B-F bonds are all evenly spaced, so that repulsion between the electrons can be minimum at this position which makes an equatorial triangle.

Arrangement of the atoms in three-dimensional way in a molecule is termed as molecular geometry. It is determined by the valence shell electron repulsion theory (VSEPR). According to VSEPR theory, a molecule will adopt a geometry in which there is minimum repulsion of valence electron pairs.

Conclusion:

The Boron trifluoride molecule is a non-polar in nature due to the two factor they are no dipole moment and the difference between the electronegativity of atoms in BF3 is 1.94 which is greater than 0.5. The geometry of Boron trifluoride is Trigonal planar and its bond angle is 120 degrees. The molecular geometry, electron geometry and VSEPR geometry of Boron Trifluoride is triagonal planar in shape.

Supriya Upadhya

I am Post Graduate in Organic chemistry with good understanding of Chemistry concepts and worked as Junior research fellow in synthesis of anti cancer agent. Also worked on Anti-Microbial Polymer synthesis as part of Post graduate thesis.

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