Question

The observed dipole moment of $HI$ is $0.38D$. Calculate the percentage ionic character of the bonding $HI$ if bond distance is $1.61$ $\dot{A}$.

• A. $16.4\%$
• B. $12\%$
• C. $5.0\%$
• D. $20\%$

Answer 1

Answer: (C)

$5.0\%$

$\text{Ionic character}=\frac{\text{Observed dipole moment}}{\text{Theoretical dipole moment}}\times 100$

$\text{Theoretical dipole moment}=(1.6\times {10}^{-19}C)\times (1.61\times {10}^{-10}m)=2.576\times {10}^{-29}Cm$

$1D=3.33564\times {10}^{-30}Cm$

$\text{Percentage ionic character}=\frac{0.38\times 3.33564\times {10}^{-30}}{2.576\times {10}^{-29}}\times 100=5\%$

Hence, option C is correct.