Question

The bond length of $HCl$ molecule is $1.275\mathring{A}$ and its dipole moment is $1.03D$. The ionic character of the molecule (in percent) (charge of the electron $=4.8\times 10^{-10}$ esu) is

• A. 100
• B. 67.3
• C. 33.66
• D. 16.83

Answer 1

Answer: (D)

Given,
observed dipole moment $=1.03D$
Bond length of $HCl$ molecule,
$d=1.275\mathring{A}$
$=1.275\times 10^{-8}cm$
Charge of electrons, $e^{-}=4.8\times 10^{-10}$ esu
Percentage ionic character $=?$
Theoretical value of dipole moment $=e\times d$
$=4.8\times 10^{-10}\times 1.275\times 10^{-8}$ esu $-cm$
$=6.12\times 10^{-18}$ esu $-cm$
$=6.12D$
Percentage ionic character
$=\frac{\text{ observed dipole moment }}{\text{ theoretical value of dipole moment }}\times 100$
$=\frac{1.03}{6.12}\times 100$
$=16.83\%$