Chemical Bonding And Molecular Structure Question 86
Question: Which bond angle $ \theta $ would result in the maximum dipole moment for the triatomic molecule $ YXY $
[AIIMS 1980]
Options:
A) $ \theta =90^{o} $
B) $ \theta =120^{o} $
C) $ \theta =150^{o} $
D) $ \theta =180^{o} $
Show Answer
Answer:
Correct Answer: A
Solution:
The dipole moment of two dipoles inclined at an angle $ \theta $ is given by the equation $ \mu =\sqrt{X^{2}+Y^{2}+2XY\cos \theta } $
$ \cos 90{}^\circ =0 $ . Since the angle increases from $ 90-180 $ , the value of $ \cos \theta $ becomes more and more - ve and hence resultant decreases. Thus, dipole moment is maximum when $ \theta =90{}^\circ $ .