NEET Solved Paper 2014 Question 20
Question: Which of the following molecules has the maximum dipole moment? [AIPMT 2014]
Options:
A) $ CO _2 $
B) $ CH _4 $
C) $ NH _3 $
D) $ NF _3 $
Show Answer
Answer:
Correct Answer: C
Solution:
- $ CO _2 $ and $ CH _4 $ have zero dipole moment as these are symmetrical in nature. Between $ NH _3 $ and $ NF _3,,NF _3 $ has greater dipole moment though in $ NH _3 $ and $ NH _3 $ both, N possesses one lone pair of electrons. This is because in case of $ NH _3 $ , the net N?H bond dipole is in the same direction as the direction of dipole of lone pair but in case of $ NH _3 $ , the direction of net bond dipole of three ?N?F bonds is opposite the that of the dipole of the lone pair. $ \because $ $ {\mu _{res}}={\mu_1}+{\mu_2}+{\mu_3}=-{\mu _{res}}=-{\mu_4}=0 $
$ \therefore $ $ {\mu _{net}}={\mu_1}+{\mu_2}+{\mu_3}+{\mu_4} $ $ =-{\mu_4}+{\mu_4}=0 $
