Question

The molecules having dipole moment are:
A) 2,2-dimethylpropane
B) trans-3-hexene
C) trans-2-pentene
D) 2,2,3,3-tetramethylbutane

Answer 1

Hint: Dipole moments occur due to the large difference in electronegativity between two chemically bonded atoms. A bond dipole moment is a measure of the polarity of a chemical bond between two atoms in a molecule. It involves the concept of electric dipole moment, it is the measure of separation of the negative and the positive charges in a system.

Complete Step by Step Solution:
The bond dipole moment is a vector, as it has both magnitude and direction. It can be noted that the symbols \[\delta \] and \[{\delta ^ - }\] represent the two electric charges that arise in a patch that is equal in magnitude but are of contrary signs. They're separated by a set (usually very small) distance, which is usually represented by the letter ‘d’.
 A dipole moment can be defined as the product of the magnitude of the charge and the distance between the centers of the positive and negative charges. It is indicated by the Greek letter ‘\[\mu \] ’.
   \[\mu \] (Dipole Moment) = Q (Charge) \[ \times \] r (distance of separation)
We know that most of the matter which is made up of atoms and molecules is electrically neutral. Depending on the behavior of the pair of charges present in the atoms, the molecules are subdivided into two major types:-
A. Polar Molecules: If the center of mass of the positive charge does not coincide with the center of mass of the negative charge then it is known as a polar molecule.
B. Non-Polar Molecules: If the center of mass of positive charge coincides with the center of mass of negative charge then it is known as a Non-Polar molecule.
The molecules having dipole moment are trans-2-pentene.
Except for the molecules of trans-2-pentene, the vector sum of each of the other 3 options is zero, hence dipole moment doesn’t exist between them.

Note: A bond dipole moment is a measure of the opposition/repulsion of a chemical bond between two titles in a patch. It involves the conception of electric dipole moment, which is a measure of the separation of negative and positive charges in a system.