Lewis Structures of Molecules with Multiple Bonds and Resonance

I. VIDEO

A)LEWIS STRUCTURE WITH MULTIPLE BONDS

B) RESONANCE STRUCTURES

C) EXCEPTIONS TO THE OCTET RULE

II. NOTES

A) LEWIS STRUCTURES WITH MULTIPLE BONDS

In some situations, simply single bonds between atoms will result in some atoms not having enough valence electrons to obey the octet rule. For example,

Draw Lewis Diagram for

• Oxygen (O₂)

• Nitrogen (N₂)

• Hydrogen cyanide (HCN)

In these situations where one "runs out of electrons," use double or triple bonds in order to obey the octet rule. For the oxygen, nitrogen, and hydrogen cyanide, their proper Lewis structures would be the following:

.. ..

:O=O: :N=N: H-C=N:

.. ..

B) LEWIS STRUCTURES THAT HAVE RESONANCE

In other situations, more than one Lewis structure can be equally valid. In this instance, one must include all resonance forms of the Lewis structure in one's answer.

Resonance Structures for ozone (O₃)

Resonance Structures for carbonate (CO₃^2-)

Resonance Structures for benzene (C₆H₆)

C) EXCEPTION TO THE OCTET RULE

However, there are exceptions to the octet rule. For example, boron has less than eight valence electrons surrounding itself, and sulfur and phosphorous may have more than eight. Below are some examples of the exceptions to the octet rule.

III.EXERCISE ABOUT LEWIS STRUCTURE WITH MULTIPLE BONDS,

RESONANCE, & EXCEPTIONS TO OCTET RULE

Click here for answers