can somebody pls explain why BF3 is non polar but NF3 is polar?

Answer 1

NF3 has one nonbonding pair of electrons, BF3 has none - complete octet.

Answer 2

Nf3 Polar Or Nonpolar

Answer 3

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BF3 is non-polar (it can violate the octet rule with molecules, as it only has 6 shared electrons instead of 8) The molecule when drawn out is symettrical, and the fluorines are aligned a good distance apart if that makes sense But in NF3, there ARE lone pairs,(it isnt an exception to the octet rule) and this pushes the fluorine bonds tighter to the bottom of the molecules, making it not semetrical, therefore polar. Typically, something with lone pairs is polar. Lewis structures and Molecular structures are good to know about when identifying whats polar and what is not

Answer 4

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RE:
can somebody pls explain why BF3 is non polar but NF3 is polar?

Answer 5

Bf3 Polar Or Nonpolar

Answer 6

In BF3 the B atom only has 6 electrons in its outer level, that is 3 pairs, and all are bonding. Maximum repulsion between these pairs ensures a bond angle of 120 degrees, with a trigonal planar shape.

In NF3 there is a lone pair, so the 4 electron pairs adopt almost a perfectly tetrahedral arrangement, but one of them is a lone pair. The 3 x F atoms are arranged in a pyramidal shape, and hold a partially negative charge, leaving the N atom with a partially positive charge.

Answer 7

Since NF3 has a lone pair on the central atom, it creates a dipole (oppositely charged sides) making distribution uneven therefore polar.

Answer 8

Polarity(measured by dipole moment) of a DIATOMIC molecule depends on polarity of the bond present between the two atoms; while in case of POLYATOMIC molecules, it is resultant of dipole moments of all the bonds present and you know that dipole moment is vector factor so in that case polarity depends on-
1. polarity of individual bonds
2. shape of the molecule.
We will look into these factors one by one.
1. in BF3 there is no lone pair of electrons on boron atom and individual dipole moment of every bond is directed from B to F while in case of NF3 there is lone pair of electrons on nitrogen atoms. the dipole moment of individual bond is directed from N to F.
2. BF3 is trigonal planar so now you draw trigonal planar molecule BF3 and show the individual dipole moment of every bond from boron to F .you can see that the resultant dipole moment is nil .
Now come to NF3. draw trigonal pyramidal structure, u find that resultant dipole moment of all the three N-F lies in between the three bonds.since N is having lone pair of electrons also so in this case dipole moment is oriented in just opposite direction to resultant dipole moment of the three N-F bonds. The dipole moment of N and lone pair of electrons is greater than the resultant dipole moment of the three N-F bond. So the DIPOLE MOMENT OF THE MOLECULE IS FROM NITROGEN TO LONE PAIR OF ELECTRONS and the molecule is polar.

Answer 9

structure of BF3 is boron(group iii) central atom surrounded by 3 fluorine atoms. boron has no lone pair of electrons so the 3 bond pairs space themselves out equally to for a trigonal planar shape. the shape of BF3 is thus a perfect equilateral triangle. there is no imbalance due to this shape, thus no polarising effect.

now nitrogen being a group V element has 5 valence electrons. 3 are used to bond to fluorines so the last 2 electrons form a lone pair. 3 bond bairs and 1 lone pair space themselves out according to VSEPR theory to form a tetrahedron. the F atoms themselves appear as a trigonal pyramid (the lone pair is not seen). since the 3 F atoms are pushed to one side of the central atom N, the molecule is polar.