Polar covalent molecules exhibit dipole moment. Dipole moment is equal to the product of charge separation, q and the bond length d for the bond. Unit of dipole moment is Debye. One Debye is equal to `10^(-18)` esu-cm.
Dipole moment is a vector quantity. It has both magnitude and direction. Hence, dipole moment of a molecule depends upon the relative orientation of the bond dipoles, but not on the polarity of bonds alone. A symmetrical structure shows zero dipole moment. Thus, dipole moment helps to predict the geometry of a molecules. Dipole moment values can be used to disinguisd between cis- and trans- isomers, ortho-, meta - and para - forms of a substance, etc.
The dipole moment value of `H-X` molecule is 1.2 Debye. If the internuclear distance between `H-X` is `0.8Å` then the `%` ionic character in `H-X` molecules is :

Options

A. `31.25%`
B. `50%`
C. `14%`
D. `25%`

Answer

A

Explanation

`%"ionic character"=(1.2xx10^(-18))/(4.8xx10^(-10)xx0.8xx10^(-8))`
`=31.25%`