Physical Properties Problem 2

Description:

Problem

Which of the following has the highest dipole moment?

a) CH₂Cl₂

b) CHCl₃

c) CCl₄

Solution

CH₂Cl₂ has the dipole moment.

Due to the symmetry of the structure, C − Cl bond dipole moments cancel each other, while C − H  dipole moments add up and gives a net dipole moment.

b) CHCl₃

Net dipole moment of 3C − Cl bond reinforces the dipole moment of C − H such that CHCl₃ has very high dipole moment.

c) CCl₄

Net dipole moment of 3C − Cl bond cancels the dipole moment of 3C − Cl bonds such that the net dipole moment of CCl₄ molecule is zero.

Thus, the order of dipole moment is: CHCl₃ > CH₂Cl₂ > CCl₄