Question

The dipole moment of $LiH$ is $1.964\times {10}^{-29}$ coulomb metre and the interatomic distance between $Li$ and $H$ in this molecule is $1.596\mathring{A}$. What is the per cent ionic charater in $LiH$? (Write answer in nearest integer value)

Answer 1

${\mu }_{molecule}=\delta \times d$
Given, $d=1.596\mathring{A}=1.596\times {10}^{-10}m$
$\mu =1.964\times {10}^{-29}culombmetre$
$\therefore 1.964\times {10}^{-29}=\delta \times 1.596\times {10}^{-10}$
$\therefore \delta =1.2306\times {10}^{-19}coulomb$
Charge on electron $=1.602\times {10}^{-19}C$
$\therefore$% ionic nature $=\frac{1.2306\times {10}^{-19}}{1.602\times {10}^{-19}}\times 100=76.82$%