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Is HBr Polar or Nonpolar?
In hydrogen bromide, bromine (2.96) is more electronegative than hydrogen (2.20), pulling the shared electrons toward itself. This creates a partial negative charge on bromine (δ−) and partial positive on hydrogen (δ+). The dipole of 0.83 D is smaller than HCl because the Br–H electronegativity difference is smaller.
Why is HBr Polar?
In hydrogen bromide, bromine (2.96) is more electronegative than hydrogen (2.20), pulling the shared electrons toward itself. This creates a partial negative charge on bromine (δ−) and partial positive on hydrogen (δ+). The dipole of 0.83 D is smaller than HCl because the Br–H electronegativity difference is smaller.
- Electronegativity difference: Br (2.96) is significantly more electronegative than H (2.2), creating partial charges on each atom and making the individual bonds polar.
- Linear shape (—): 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 0.83 D.
- Net dipole moment (0.83 D): Any molecule with a nonzero net dipole moment is classified as polar. The 0.83 D dipole moment of HBr confirms its polar character.
Molecular Geometry of HBr
HBr has a linear molecular geometry with a bond angle of —. Here is why this shape determines polarity:
- The central atom's electron pairs arrange themselves to minimize repulsion, resulting in the linear shape.
- The — bond angle creates an asymmetric arrangement — the bond dipoles point in directions that do not perfectly oppose each other.
- Asymmetry is the key: if HBr had a perfectly symmetric geometry, its bond dipoles would cancel and the molecule would be nonpolar. The linear 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 HBr:
- H (central atom) electronegativity: 2.2
- Br (outer atom) electronegativity: 2.96
- Difference: 0.76 — above the ~0.5 threshold, so the H–Br bonds are polar
The combination of polar bonds and an asymmetric linear geometry means the partial charges do not cancel — making HBr a polar molecule with a net dipole of 0.83 D.
Is HBr Polar or Nonpolar? (Quick Answer)
HBr (Hydrogen Bromide) is polar. HBr is a polar molecule because bromine is more electronegative than hydrogen, creating a permanent bond dipole of 0.83 D.
Frequently Asked Questions
Is HBr polar or nonpolar?
HBr is a polar molecule because bromine is more electronegative than hydrogen, creating a permanent bond dipole of 0.83 D.
Why is Hydrogen Bromide polar?
In hydrogen bromide, bromine (2.96) is more electronegative than hydrogen (2.20), pulling the shared electrons toward itself. This creates a partial negative charge on bromine (δ−) and partial positive on hydrogen (δ+). The dipole of 0.83 D is smaller than HCl because the Br–H electronegativity difference is smaller.
What is the shape of HBr?
HBr has a linear molecular geometry with a bond angle of —. This shape results in an asymmetric charge distribution and a net dipole moment of 0.83 D, making the molecule polar.
Does HBr have a dipole moment?
Yes. HBr has a dipole moment of 0.83 D. Its linear geometry and polar bonds combine to produce a net dipole, confirming its polar character.