Which of the following molecules has a net dipole moment of zero?
A)I
B)II
C)III
D)IV

Question

Which of the following molecules has a net dipole moment of zero? 
A)I 
B)II 
C)III 
D)IV

Quizplus · Accepted Answer

In molecule I, the electronegativities of C and O are different, and the shape of the molecule is not symmetrical, so there is a dipole moment. In molecule II, the electronegativities of C and H are similar and the molecule is symmetrical, so the dipole moments cancel each other out, resulting in a net dipole moment of zero. In molecule III, the electronegativities of N and O are different, and the molecule is not symmetrical, so there is a dipole moment. In molecule IV, the electronegativities of C and H are similar, and the molecule is symmetrical, resulting in a net dipole moment of zero.

Which of the Following Molecules Has a Net Dipole Moment