Chemical Bonding And Molecular Structure Question 475
Question: Which one of the following arrangements of molecules is correct on the basis of their dipole moments-
Options:
A) $ BF_3>NH_3>NF_3 $
B) $ BF_3>NF_3>NH_3 $
C) $ NH_3>BF_3>NF_3 $
D) $ NH_3>NF_3>BF_3 $
Show Answer
Answer:
Correct Answer: D
Solution:
- Both $ NF_3 $ and $ NH_3 $ have identical shape and a lone pair of electrons on nitrogen. The dipole moment of $ NH_3 $ is higher than $ NF_3 $ due to different directions of moments of the N - F and N - H bond. BF is a symmetrical molecule. It has zero dipole moment.