Question

Statement 1 : Among nitrogen halides $NX_3$, the dipole moment is highest for $NI_3$ and lowest for $NF_3$
Statement 2 : Nitrogen halides $NX_3$, have trigonal pyramidal structure.

• A. If both Statement $1$ and Statement $2$ are true and the statement $2$ is the correct explanation of the statement $1$
• B. If both Statement $1$ and Statement $2$ are true but statement $2$ is not the correct explanation of the statement $1$
• C. If Statement $1$ is true but Statement $2$ is false
• D. If Statement $1$ is false but Statement $2$ is true

Answer 1

Answer: (B)

Both statements are true but statement $2$ is not the correct explanation of statement $1$.
In case of $NI_3$, the lone pair moment adds on the resultant of the $N - 1$ moments but in case of $NF_3$, the lone pair moment on partly cancels the resultant moments.