Question

Dipole moment of $HCl =1.03 D , HI =0.38 \,D$. Bond length of $HCl =1.3 \mathring{A}$ and $HI =1.6 \mathring{A}$. The ratio of fraction of electric charge, $\delta$, existing on each atom in $HCl$ and $HI$ is

• A. 12 : 1
• B. 2.7 : 1
• C. 3.3 : 1
• D. 1 : 3.3

Answer 1

Answer: (C)

From the definition of dipole moment,

$\mu=\delta \times d$

where, $\delta=$ magnitude of electric charge

$d=$ distance between particles (here bond length)

$\therefore \delta=\frac{\mu}{d}$

or, $\frac{\delta_{ HCl }}{\delta_{ HI }} =\frac{\mu_{ HCl }}{d_{ HCl }} \times \frac{d_{ HI }}{\mu_{ HI }} $

$=\frac{1.03 \times 1.6}{1.3 \times 0.38}=3.3: 1$