Question

8. Which of the following molecule has max dipole moment?

1. $C{O}_2$

2. $C{H}_4$

3. $N{H}_3$

4. $N{F}_3$

Answer 1

The explanation for the correct option:

Option(3)

$N{H}_3$



• Among nitrogen and hydrogen, nitrogen is more electronegative and so the hydrogen gives dipole toward nitrogen.
• And nitrogen gives dipole toward lone pair.
• The direction of the lone pair dipole moment and the bond pair dipole moment is the same. so there is a net dipole in one direction.
• The molecular geometry is pyramidal.

The explanation for the incorrect option:

1.

$C{O}_2$





• ​$C{O}_2$ has a linear structure, there is a bond dipole moment between the $C-O$ bonds.
• But, as the dipole moment of one bond is canceled by the other, hence the dipole moment is zero.

2. $C{H}_4$

• ​It has zero dipole moment because it is tetrahedral in shape and each bond pair are at an equal distance which means these are symmetrically arranged hence each dipole moment of bond balance each other

4. $N{F}_3$

• ​Among nitrogen and fluorine, fluorine is more electronegative, hence the dipole is towards the fluorine atom.
• N-F bonds are in the opposite direction, so they partly cut the bond moment of the lone pair.

Hence, Option(3) $N{H}_3$ is the molecule with a higher dipole moment.