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Is PF3 Polar or Nonpolar?
Phosphorus trifluoride has a trigonal pyramidal geometry with a lone pair on phosphorus. Fluorine (3.98) is much more electronegative than phosphorus (2.19), creating strongly polar P–F bonds. The pyramidal shape prevents the three P–F dipoles from canceling, and the lone pair adds to the net dipole, giving PF3 a moment of 1.03 D.
Why is PF3 Polar?
Phosphorus trifluoride has a trigonal pyramidal geometry with a lone pair on phosphorus. Fluorine (3.98) is much more electronegative than phosphorus (2.19), creating strongly polar P–F bonds. The pyramidal shape prevents the three P–F dipoles from canceling, and the lone pair adds to the net dipole, giving PF3 a moment of 1.03 D.
- Electronegativity difference: F (3.98) is significantly more electronegative than P (2.19), creating partial charges on each atom and making the individual bonds polar.
- Trigonal Pyramidal shape (97.8°): The asymmetric molecular geometry means the bond dipoles point in directions that do not cancel — they add up to produce a net dipole moment of 1.03 D.
- Net dipole moment (1.03 D): Any molecule with a nonzero net dipole moment is classified as polar. The 1.03 D dipole moment of PF3 confirms its polar character.
Molecular Geometry of PF3
PF3 has a trigonal pyramidal molecular geometry with a bond angle of 97.8°. Here is why this shape determines polarity:
- The central atom's electron pairs arrange themselves to minimize repulsion, resulting in the trigonal pyramidal shape.
- The 97.8° bond angle creates an asymmetric arrangement — the bond dipoles point in directions that do not perfectly oppose each other.
- Asymmetry is the key: if PF3 had a perfectly symmetric geometry, its bond dipoles would cancel and the molecule would be nonpolar. The trigonal pyramidal shape prevents this cancellation.
Electronegativity and Polarity
Electronegativity measures how strongly an atom attracts bonding electrons. A difference greater than ~0.5 on the Pauling scale generally means the bond is polar.
In PF3:
- P (central atom) electronegativity: 2.19
- F (outer atom) electronegativity: 3.98
- Difference: 1.79 — above the ~0.5 threshold, so the P–F bonds are polar
The combination of polar bonds and an asymmetric trigonal pyramidal geometry means the partial charges do not cancel — making PF3 a polar molecule with a net dipole of 1.03 D.
Is PF3 Polar or Nonpolar? (Quick Answer)
PF3 (Phosphorus Trifluoride) is polar. PF3 is a polar molecule because its trigonal pyramidal shape and the large electronegativity difference between phosphorus and fluorine create a net dipole of 1.03 D.
Frequently Asked Questions
Is PF3 polar or nonpolar?
PF3 is a polar molecule because its trigonal pyramidal shape and the large electronegativity difference between phosphorus and fluorine create a net dipole of 1.03 D.
Why is Phosphorus Trifluoride polar?
Phosphorus trifluoride has a trigonal pyramidal geometry with a lone pair on phosphorus. Fluorine (3.98) is much more electronegative than phosphorus (2.19), creating strongly polar P–F bonds. The pyramidal shape prevents the three P–F dipoles from canceling, and the lone pair adds to the net dipole, giving PF3 a moment of 1.03 D.
What is the shape of PF3?
PF3 has a trigonal pyramidal molecular geometry with a bond angle of 97.8°. This shape results in an asymmetric charge distribution and a net dipole moment of 1.03 D, making the molecule polar.
Does PF3 have a dipole moment?
Yes. PF3 has a dipole moment of 1.03 D. Its trigonal pyramidal geometry and polar bonds combine to produce a net dipole, confirming its polar character.