Chapter U2.17, Problem 7E

Interpretation Introduction

Interpretation : Three pairs of atoms with polar covalent bonds with difference in their electronegativity values are to be named.

Concept Introduction :

The tendency of an atom to attract shared electrons is called electronegativity. When two atoms with different electronegativity values form a covalent bond with each other, the resultant bond is called polar covalent bond.

Answer to Problem 7E

Three pairs of atoms with polar covalent bonds are:

1. CO- It has an electronegativity difference of 0.89
2. HF-It has an electronegativity difference of 1.88
3. HCl- It has an electronegativity difference of 1.06

Explanation of Solution

When the difference in electronegativity between two atoms is more than 0 and less than 2.1, the bond is polar covalent.

1. CO- From the electronegativity scale, electronegativity value of carbon is 2.55 and oxygen is 3.44. Difference in electronegativity value= 3.44-2.55=0.89
2. H-F- From the electronegativity scale, electronegativity value of hydrogen is 2.10 and fluorine is 3.98. Difference in electronegativity value=3.98-2.10=1.88
3. HCl- From the electronegativity scale, electronegativity value of hydrogen is 2.10 and chlorine is 3.16. Difference in electronegativity value=3.16-2.10=1.06

Conclusion

In a polar molecule one atom is more electronegative than other atom. In polar covalent molecule the difference in electronegativity value is more than 0 and less than 2.1.