Question

The correct order of polar nature in the covalent bond of the following character
\[
  A.{\text{ }}HF > HCl > HBr > HI \\
  B.{\text{ }}HF > HCl > HI \\
  C.{\text{ }}HF > HBr > HI \\
  D.{\text{ None of the above}} \\
 \]

Answer 1

Hint- In order to deal with this question we will use the concept that the polar nature of covalent bond depends on the symmetry between the elements where the covalent bond is formed. So primarily we will look for the symmetry in the compounds.

Complete answer:
In the periodic table as we come down in the halogen group the electronegativity of atoms will be decreasing which leads to the decrease in tendency of attracting electrons towards itself which makes the electrons between atoms of elements unsymmetrical.
This asymmetry leads to formation of less polar covalent bond and in periodic table as we come down the group from F to I.
As we know that the correct order from fluorine to iodine is \[F > Cl > Br > I\]
Hence, the correct order of polar nature in the covalent bonds of the following character is \[HF > HCl > HBr > HI\]

So, the correct option is A.

Additional information-
Covalent bond, also called a molecular bond, is a chemical bond which involves the sharing of pairs of electrons among atoms. Such electron pairs are known as shared pairs or bonding pairs, and when they share electrons, the stable equilibrium of attractive and repulsive forces between atoms is known as covalent bonding. Sharing of electrons for many molecules allows each atom to obtain the equivalent of a full outer shell, leading to a stable electronic configuration. Covalent bonds are much more common in organic Chemistry than ionic bonds.

Note- Polar covalent bond is a chemical bond of chemical bonding in which a pair of electrons are exchanged unequally between two atoms. The electrons are not shared equally in a polar covalent bond, because one atom spends more time with the electrons than the other atom. The electronegativity of an element helps us to determine how much electrons it wishes to gain or lose in a chemical reaction and its compound is ionic, polar or nonpolar due to the difference in electronegativity.