PPT Slide

Lewis structures for molecules with multiple bonds.

Step 5. For multiple bonds. If, after Step 4, a central atom lacks an octet, use a lone pair from a bonded atom to make a multiple bond.

Writing Lewis Structures for Molecules with Multiple Bonds

Problem: Write Lewis structures for the following:

(a) Ethylene (C 2H 4) (b) Nitrogen (N 2)

Solution: (a) For C 2H 4. After Steps 1 to 4 :

In some Lewis structures, after Step 4, there are not enough electrons for the central atom (or atoms) to attain an octet.

This usually means that a multiple bond is present, and an additional step is needed:

Notes: