Chapter U2.16, Problem 6E

Interpretation Introduction

Interpretation:Whether the molecule HOCl is polar or non-polar needs to be explained using the Lewis dot structure.

Concept Introduction:  Molecules are divided into two on the basis of their polarity- polar and non-polar.

Answer to Problem 6E

When two atoms do not share equal electrons in a covalent bond, the molecule becomes polar, whereas when there is equal sharing of electrons between atoms, it becomes non-polar.

Explanation of Solution

In the case of HOCl molecule, two covalent bonds are formed in between Cl-O and O-H, both are formed by an equal number of electrons. A polar molecule must contain polar bonds due to the difference between the bonded atoms. Another way to find out the polarity of any molecule is its electronegativity difference. If electronegativity difference is less than 0.5, then the molecule is considered as non-polar.

The Lewis dot structure of HOCl is represented as follows:

The electronegativity difference between O (3.4)and Cl (3.2) atom is 0.2 thus, it has polar covalent bond.

Also, the electronegativity difference between O (3.4) and H (2.2) is 1.2 thus, it also has polar covalent bond.

The molecule has bent shape and there are two lone pair of electrons on O atom. Therefore, overall molecule is non-polar in nature.