Chapter U2.17, Problem 2E

Interpretation Introduction

Interpretation : The atom in a covalent bond that is partially positive needs to be identified.

Concept Introduction :

A covalent bond is formed when there is sharing of electrons between the atoms to fulfill the noble gas configuration. When two atoms with different electronegativity value form a covalent bond with each other, the resultant bond is called polar covalent bond.

Answer to Problem 2E

In a polar covalent bond, atom with higher electronegativity value attracts more electrons than atom with low electronegativity value. Atoms that are less electronegative will have positive charge.

Explanation of Solution

In a polar covalent molecule the bonded pair of electrons is not shared equally among the atoms. For example in HCl molecule, the hydrogen and chlorine atom do not share the bonded pair of electrons equally. Atom with higher electronegativity attracts more electrons than atom with low electronegativity. Atoms that are more electronegative have partial negative charge and atoms that are less electronegative have partial positive charge.

HCl has polar covalent bond between hydrogen atom and chlorine atom as difference between electronegativity value of hydrogen (2.10) and of chlorine (3.16) is 1.06. Here hydrogen has less value than chlorine so it will have partial positive charge and chlorine will have partial negative charge.

Conclusion

In a covalent bond atom with less electronegative value will develop partial positive charge.