Chapter 8, Problem 101A

Interpretation Introduction

Interpretation:

Resonance structure of ${\text{CO}}_3^{2-}$ needs to be explained.

Concept introduction:

A Resonance structure is the two or more correct Lewis structures which indicate a single molecule or ion. These structures differ only in electron pairs position. The location of atom is same in resonance structure.

Answer to Problem 101A

Resonance structure of ${\text{CO}}_3^{2-}$are as follows:

Explanation of Solution

Resonance is a condition for those molecules which have more than one valid Lewis structure. The ${\text{CO}}_3^{2-}$

molecules have three possible Lewis structure. In this structure, only position of double bond and electron pairs are different. Valence electron of O is 6 and C is four and two extra electrons are added due to two negative charge. Thus, to complete octet C forms a double bond with any of one oxygen atom out of three. Hence, the resonance structure is as follows:

Conclusion

Each molecule or ion that undergoes resonance behaves as if it has only one structure.