The dipole moment of a molecule of carbon tetrachloride is zero because
- A. the carbon to chlorine bonds are non polar
- B. the four polar bonds are arranged symmetrically so their dipoles cancel
- C. chlorine and carbon have the same electronegativity
- D. the molecule is planar
Explanation
Each bond carries a substantial dipole, but the tetrahedral symmetry means the four vectors sum to zero, leaving the molecule non polar overall. Replacing one chlorine with hydrogen destroys the symmetry and gives chloroform a measurable dipole moment. Shape therefore matters as much as bond polarity in deciding whether a molecule is polar.