Question

Dipole moment of CO₂ molecule is zero where as SO₂ has some dipole moment. Explain the reason.

Answer 1

The best way to understand geometry is by drawing the Lewis dot structure of the molecules.

The geometry of CO₂ is linear (electron geometry is linear too) because the two bonds are the farthest apart and the bond angle is 180°. This is what makes of CO₂ a non polar molecule because the dipole moments of both bonds cancel out.

The geometry of SO₂ is bent (electron geometry is trigonal planar) because the lone pair on the central sulphur atom pushes the two bonds down for a bond angle of 120° due to the electrons repulsion. This is what makes of SO₂. a polar molecule because the dipole moments of both bonds do not cancel out, and the molecule will have a net dipole moment.