Question

The observed dipole moment of $HCl$ is $1.03D$. Bond length is $1.275{A^ \circ }$ then the percentage of ionic character is.
1)$16.83\% $
2) $21\% $
3) $30.72\% $
4) $14.21\% $

Answer 1

Hint: We know that a moment arises in any system during which there's a separation of charge is called a dipole moment. They can, therefore, arise in ionic bonds also as in covalent bonds. Dipole moments arise due to the difference in electronegativity between two chemically bonded atoms.

Complete step by step solution:
We have to remember that the ionic bonding is a kind of substance holding that includes the electrostatic fascination between oppositely charged ions or between two molecules with pointedly extraordinary electronegativities and is the essential association happening in ionic mixes. It is one of the principle kinds of holding alongside covalent holding and metallic holding.
We have to know that the particles are molecules with an electrostatic charge. Iotas that gain electrons make contrarily charged particles. Molecules that lose electrons make decidedly charged particles. This exchange of electrons is known as electrovalence rather than covalence.
Recognize that perfect ionic bonding in which one particle or atom totally moves an electron to another can't exist: all ionic mixes have some level of covalent holding, or electron sharing. Hence, the expression ionic bonding is given when the ionic character is more noteworthy than the covalent character that is, a bond wherein an enormous electronegativity distinction exists between the two atoms, making the holding be more polar (ionic) than in covalent holding where electrons are shared all the more similarly.
Thus the dipole moment can be calculated as,
Dipole moment$ = e \times d = 4.8 \times {10^{ - 10}} \times 1.275 \times {10^{ - 8}}$
Dipole moment$ = 6.12 \times {10^{ - 18}}$
We can calculate the percentage of ionic character from the dipole moment value as follows,
$\% {\text{of ionic character}} = \dfrac{{{\text{Observed dipole moment}}}}{{{\text{Calculated dipole moment}}}} \times 100$
Substitute the known values we get,
% of ionic character$ = \dfrac{{1.03}}{{6.12}} \times 100 = 16.83\% $
Therefore, the option A is correct.

Note:We know that polarity results from the uneven partial charge distribution between various atoms in a compound. Atoms, like nitrogen, oxygen, and halogens that are more electronegative tend to have partial negative charges. Atoms, like carbon and hydrogen, tend to be more neutral or have partial positive charges.
The polar nature of the molecules can be measured by the dipole moment. A molecule with zero dipole moment then it is a nonpolar molecule. If a molecule has a net dipole moment then it is a polar molecule.