Question

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

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

Answer 1

The correct option is B in $N{H}_3$ the atomic dipole and bond dipole is in the same direction whereas in $N{F}_3$ these are in opposite directions.

In $N{H}_3$ the atomic dipole and bond dipole are in opposite direction.

Electronegativity of $N$ is greater than that of $H$, but in $N{F}_3$, electronegativity of $F$ is greater than that of $N$, So, in $N{H}_3$ the atomic dipole and bond dipole are in the same direction whereas $N{F}_3$ there are in opposite directions.