Question

From among the 4 given compounds identify the compounds which possess a net dipole moment.

• A. A and D
• B. D and B
• C. A and C
• D. B and C

Hint:

A molecule has a net dipole moment if the individual bond dipoles do not cancel each other out due to the molecular geometry. In a symmetrical molecule, dipoles cancel out, resulting in no net dipole moment.

Answer 1

The Correct Option is C

Step 1: Analyze the dipole moment of cis-1,2-dichloroethene.
In cis-1,2-dichloroethene, the two chlorine atoms are attached to the same side of the double bond, which creates a dipole moment due to the electronegativity difference between chlorine and hydrogen. This results in a net dipole moment.

Step 2: Analyze the dipole moment of tetrachloromethane.
Tetrachloromethane (CCl\(_4\)) has a symmetrical tetrahedral shape, with four chlorine atoms symmetrically arranged around the central carbon atom. Since the individual dipoles cancel each other out, CCl\(_4\) does not have a net dipole moment.

Step 3: Analyze the dipole moment of o-dichlorobenzene.
O-dichlorobenzene has two chlorine atoms attached to the benzene ring in an ortho position. The non-symmetrical arrangement of the chlorine atoms creates a net dipole moment.

Step 4: Analyze the dipole moment of trans-2,3-dibromobut-2-ene.
Trans-2,3-dibromobut-2-ene is symmetrical, and the individual dipoles cancel out due to the linear arrangement of the bromine atoms on opposite sides of the double bond. Hence, it has no net dipole moment.

Step 5: Conclusion.
Thus, the compounds that possess a net dipole moment are cis-1,2-dichloroethene (A) and o-dichlorobenzene (C). Therefore, the correct answer is option (C).