Is Sulfur Dioxide (SO₂) Polar or Nonpolar?

Is Sulfur Dioxide (SO₂) polar or nonpolar?

SO₂ has two polar S=O bonds (ΔEN = 0.86). The bent geometry (119.5°) means the dipoles do not point in opposite directions, so they don't cancel. The lone pair on sulfur reinforces the asymmetry.

FormulaSO₂
PolarityPolar
Molecular GeometryBent
S=O BondΔEN = 0.86 (polar)
Net DipoleYes

Bond Dipoles

Each S=O bond has ΔEN = 0.86 (O = 3.44, S = 2.58). Oxygen pulls electron density away from sulfur in both bonds. These are moderately polar bonds.

Molecular Shape & Dipole Cancellation

SO₂ is bent (119.5°) because sulfur has one lone pair occupying the third position around its sp² center. Compare to CO₂ which is linear - the lone pair makes the difference.

Net Dipole Moment

The two S=O dipoles are at 119.5° to each other - they partially reinforce rather than cancel. Plus the lone pair adds to the asymmetry. SO₂ is polar, which is why it dissolves in water to form sulfurous acid.

See bond dipoles, partial charges, and net dipole moments on interactive 3D molecules.

Visualize Sulfur Dioxide's Polarity in 3D

Related Topics