Chapter U2.43, Problem 3E

Interpretation Introduction

Interpretation:

The reason for carbon dioxide to be nonpolar molecule even though its bonds are polar is to be explained.

Concept introduction:

There are two classes of molecules; polar and nonpolar. There are partial charges on atoms of a polar molecule. A polar molecule has a dipole as it has two poles; a positive end and a negative end.

Answer to Problem 3E

A polar molecule is a molecule that possesses partial charges on its atoms. In carbon dioxide molecules, the two dipole moments in CO₂ balance each other, and there is no partial positive or negative charge on the molecule. So the overall molecule is nonpolar.

Explanation of Solution

In a carbon dioxide molecule, there is a double bond between carbon and oxygen atom. These bonds are polar. So there are two polar bonds in a molecule of CO₂. Oxygen is more electronegative than carbon so both oxygen atoms pull the electrons away from the carbon atom in opposite directions. Both the dipoles in CO₂ balance each other, and there is no partial positive or negative charge on the molecule. So the overall molecule is nonpolar.

Conclusion

Carbon dioxide is a nonpolar molecule even though its bonds are polar as the two dipoles cancel out each other and there is no net charge on the molecule.