Question

The electronegativity difference between $N$ and $F$ is greater than $N$ and $H$, yet the dipole moment of $N{H}_3$ (1.5 D) is greater than that of $N{F}_3$ (0.2 D). This is because :

• A. in $N{H}_3$ as well as $N{F}_3$, the atomic dipole and bond dipole are in the opposite direction.
• B. in $N{H}_3$, the atomic dipole and bond dipole are in the opposite direction, whereas in $N{F}_3$ these are in the same direction.
• C. in $N{H}_3$ as well as in $N{F}_3$ the atomic dipole and bond dipole are in the same direction.
• D. in $N{H}_3$ the atomic dipole and bond dipole are in the same direction, whereas in $N{F}_3$ these are in the opposite direction.

Answer 1

Answer: (D)

in $N{H}_3$ the atomic dipole and bond dipole are in the same direction, whereas in $N{F}_3$ these are in the opposite direction.

Though the electronegativity difference between $N$ and $F$ is greater than $N$ and $H$, yet the dipole moment of $N{H}_3$ (1.5 D) is greater than that of $N{F}_3$(0.2 D) because in $N{H}_3$ the atomic dipole and bond dipole are in the same direction, whereas in $N{F}_3$ these are in the opposite direction.