Chapter U2.18, Problem 1E

Interpretation Introduction

Interpretation : Method to determine polarity of a molecule is to be explained.

Concept Introduction :

Molecules smell differently. Small molecules which are polar in nature have a smell. Small molecules that are non-polar generally do not have a smell.

Answer to Problem 1E

The overall shape of a molecule determines the polarity of the molecule. Asymmetric molecules are polar. Molecules that have irregular shape tend to be polar in nature.

Explanation of Solution

It is not necessary that if the bonds between atoms are polar, the whole molecule will be polar. The overall shape of the molecule determines the polarity of the molecule. If the shape is asymmetric the molecule will be polar. Example: Ammonia, NH₃ and water, H₂O are asymmetric molecules. So they are polar. There are partial positive charges on hydrogen atoms and partial negative charge on nitrogen and oxygen atoms.

Conclusion

Small polar molecules have smell. If the shape of the molecule is symmetrical it will be nonpolar and if shape is asymmetrical the molecule will be polar.