Question

A diatomic molecule has dipole moment of 1.2 D. If the bond distance is $1.0\stackrel{\circ }{A}$, what fraction of charge e exists on each atom?

• A. 1
• B. 0.5
• C. 0.25
• D. 0.125

Answer 1

The correct option is C

0.25

WKT, $\mu =q\times d$ where $\mu$ = dipole moment

$q$ = charge

$d$ = distance

$\therefore$ $\mu$ = $1.2D$

$d$ = $1.0\AA$

$q$ = $\frac{1.2D}{1.0\stackrel{0}{A}}$ = $\frac{1.2\times {10}^{-18}}{1.0\times {10}^{-8}}$ = $1.2\times {10}^{-10}esu$

since proton (+1) and electron (-1) have a dipole moment of $4.8D$ when separated by $100pm$ distance,

fraction of electronic charge = $\frac{1.2\times {10}^{-10}}{4.8\times {10}^{-10}}=0.25$