Lewis Dot

Lewis Dot 6 - Resonance
Two or more equivalent structures with double bonds
Index:
A Rule 6 - Resonance
B
C
Example 1 - HCO 2 G
Example 2 - C 6 H 6
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Lewis Dot 6: Resonance
If there are two or more equivalent ways to place
a double bond in a molecule, this is an indication
of resonance. This is shown by drawing all
possibilities and writing a double arrow (ø)
between them.
2

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 1: What is the Lewis Dot structure of
the HCO 2 G ion?
3

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 1: What is the Lewis Dot structure of
the HCO 2 G ion?
Here is the structure using rules 1 - 6:
H–C
O
O:
4

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 1: What is the Lewis Dot structure of
the HCO 2 G ion?
Here is the structure using rules 1 - 6:
H–C
O
O:
H–C
O
O:
But why is the “=” to top and not bottom “O”?
5

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 1: What is the Lewis Dot structure of
the HCO 2 G ion?
Here is the structure using rules 1 - 6:
H–C
O
O:
H–C
O
O:
The answer: “They are both correct.”
6

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 1: What is the Lewis Dot structure of
the HCO 2 G ion?
Here is the structure using rules 1 - 6:
H–C
O
O:
ø
H–C
O
O:
Therefore, show both with a “ø” between them.
7

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 2: What is the Lewis Dot structure of
the C 6 H 6 molecule (a ring molecule)?
8

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 2: What is the Lewis Dot structure of
the C 6 H 6 molecule (a ring molecule)?
Here is the structure using rules 1 - 6:
H
H
H
C
C C
C C
C
H
H
H
9

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 2: What is the Lewis Dot structure of
the C 6 H 6 molecule (a ring molecule)?
Here is the structure using rules 1 - 6:
H
H
H
C
C C
C C
C
H
H But, why
not this? !
H
H
H
H
C
C C
C C
C
H
H
H
10

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 2: What is the Lewis Dot structure of
the C 6 H 6 molecule (a ring molecule)?
Here is the structure using rules 1 - 6:
H
H
There is no
H
C
C C
H difference, H
C
C C
C C
so insert
C C
H H “ø” H C
C
H
H
H
H
11

Lewis Dot 6: Resonance
If there are 2 or more equivalent ways to place a double
bond, this indicates resonance. show all possibilities and
writing a”ø” between them.
Example 2: What is the Lewis Dot structure of
the C 6 H 6 molecule (a ring molecule)?
Here is the structure using rules 1 - 6:
H
H
H
C
C C
C C
C
H
H
H
ø
H
H
H
C
C C
C C
C
H
H
H
12

Lewis Dot 6 - Resonance
Two or more equivalent structures with double bonds
THE END
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