Which of the following has the highest dipole moment?

Options

A. o-Dichlorobenzene
B. m-Dichlorobenzene
C. p-Dichlorobenzene
D. All have equal values

Answer

A

Explanation

In p-dichlorobenzene, the two `C-Cl` bond dipoles (equal in magnitude and opposite in direction) cancel each other. In o-dichlorobenzene, the vertical component of one `C-Cl` bond dipole reinforces the bond dipole of other `C-Cl` bond dipoles (equal in magnitude and opposite in direction) cancel each other. In o-dichlorobenzene, the vertical component of one `C-Cl` bond dipole reinforces the bond dipole of other `C-Cl` bond while in m-dichlorobenzene, the vertical component of one `C-Cl` bond dipole opposes the bond dipole of another `C-Cl` bond.