Chemical Bonding And Molecular Structure Ques 56
56. The dipole moments of diatomic molecules $A B$ and $C D$ are $10.41 D$ and $10.27 D$, respectively while their bond distances are 2.82 and $2.67 \AA$, respectively. This indicates that
[1999]
(a) bonding is 100% ionic in both the molecules
(b) $A B$ has more ionic bond character than $C D$
(c) $A B$ has lesser ionic bond character than $C D$
(d) bonding is nearly covalent in both molecules
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Solution:
- (c) As dipole moment $=$ electric charge $\times$ bond length
D. M. of $AB$ molecules
$=4.8 \times 10^{-10} \times 2.82 \times 10^{-8}=1.353 \times 10^{-16} D$
D.M. of $CD$ molecules
$=4.8 \times 10^{-10} \times 2.67 \times 10^{-10}=1.281 \times 10^{-18} D$
now % ionic character
$=\frac{\text{ Actual dipole moment of the bond }}{\text{ Dipole moment of pure ionic compound }}$
$%$ ionic character of
$A B=\frac{10.41}{13.53} \times 100=76.94 \%$
$%$ ionic character of
$C D=\frac{10.27}{12.81} \times 100=80.23 \%$
BETA
