Question

Which bond angle θwould result in the maximum dipole moment for the triatomic molecule YXY

• A. θ=90°
• B. θ=120°
• C. θ=150°
• D. θ=180°

Answer 1

The correct option is A

θ=90°

The dipole moment of two dipoles inclined at an angle $\theta$ is given by the equation

$\mu =\sqrt{X^2+Y^2+2XYcos\theta }$

$cos{90}^o=0$. 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 $\theta ={90}^o$.