Question

Which of the following statement is INCORRECT?

• A. The dipole moment of $BF_{3}$ is zero.
• B. The bond order of CO molecule is the same as the bond order in $NO^{+}$ ion.
• C. In ozone molecule, the two O-O bond lengths are equal.
• D. The dipole moment of $NF_{3}$ is much greater than that in $NH_{3}$
• E. Carbonate ion has three canonical forms.

Hint:

In $NH_{3}$, $\mu$ directions add up; in $NF_{3}$, they partially cancel.

Answer 1

The Correct Option is D

Step 1: Concept
Dipole moment depends on the vector sum of bond dipoles and lone pair dipoles.

Step 2: Meaning
In $NH_{3}$, the lone pair and bond dipoles are in the same direction; in $NF_{3}$, they oppose each other.

Step 3: Analysis
Because they oppose, $\mu$ of $NF_{3}$ is much smaller than $NH_{3}$. Statement D is false.

Step 4: Conclusion
Statement D is incorrect. Final Answer: (D)