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Is PF5 Polar or Nonpolar?
Phosphorus pentafluoride has a trigonal bipyramidal geometry with no lone pairs. Each P–F bond is strongly polar (F is much more electronegative than P), but the three equatorial bonds cancel among themselves and the two axial bonds cancel each other, giving PF5 a net dipole of 0 D.
Why is PF5 Nonpolar?
Phosphorus pentafluoride has a trigonal bipyramidal geometry with no lone pairs. Each P–F bond is strongly polar (F is much more electronegative than P), but the three equatorial bonds cancel among themselves and the two axial bonds cancel each other, giving PF5 a net dipole of 0 D.
- Symmetric trigonal bipyramidal geometry (90° / 120°): The atoms are arranged symmetrically around the central atom. This forces all bond dipoles to point in directions that cancel each other out exactly.
- Polar bonds that cancel: The electronegativity difference between F (3.98) and P (2.19) creates polar bonds — but the trigonal bipyramidal shape ensures their dipoles cancel perfectly.
- Zero net dipole (0 D): Because all bond dipoles cancel, the net dipole moment is 0 D. Any molecule with zero net dipole moment is classified as nonpolar.
Molecular Geometry of PF5
PF5 has a trigonal bipyramidal molecular geometry with a bond angle of 90° / 120°. Here is why this shape determines polarity:
- The trigonal bipyramidal arrangement places all outer atoms at equal angles (90° / 120°) from the central atom, creating perfect spatial symmetry.
- Each bond dipole has an equal and opposite counterpart — they cancel in pairs, leaving no net charge separation.
- Symmetry is the key: even if the individual bonds are polar, the trigonal bipyramidal geometry ensures a net dipole of 0 D.
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 PF5:
- 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
Even though the individual bonds are polar (difference = 1.79), the trigonal bipyramidal geometry of PF5 causes them to cancel completely. Polarity depends on both bond polarity AND molecular shape.
Is PF5 Polar or Nonpolar? (Quick Answer)
PF5 (Phosphorus Pentafluoride) is nonpolar. PF5 is a nonpolar molecule because its trigonal bipyramidal symmetry causes all five polar P–F bond dipoles to cancel in symmetric pairs.
Frequently Asked Questions
Is PF5 polar or nonpolar?
PF5 is a nonpolar molecule because its trigonal bipyramidal symmetry causes all five polar P–F bond dipoles to cancel in symmetric pairs.
Why is Phosphorus Pentafluoride nonpolar?
Phosphorus pentafluoride has a trigonal bipyramidal geometry with no lone pairs. Each P–F bond is strongly polar (F is much more electronegative than P), but the three equatorial bonds cancel among themselves and the two axial bonds cancel each other, giving PF5 a net dipole of 0 D.
What is the shape of PF5?
PF5 has a trigonal bipyramidal molecular geometry with a bond angle of 90° / 120°. This shape causes all bond dipoles to cancel perfectly, giving a net dipole of 0 D and making the molecule nonpolar.
Does PF5 have a dipole moment?
No. PF5 has a dipole moment of 0 D. Its trigonal bipyramidal geometry causes all individual bond dipoles to cancel out completely, resulting in a nonpolar molecule.