Chemistry Reference
In-Depth Information
The carbon has a -1 formal charge, and the oxygen has a +1
formal charge. Carbon monoxide is isoelectronic with cyanide ion
but has no net charge (-1 + 1 = 0).
g.
BF
3
There are 24 valence electrons (B = 3, F = 7). The structure is
usually written with only 6 electrons around the boron.
In this case, there are no formal charges. This structure shows
that BF
3
is a Lewis acid, which readily accepts an electron pair to
complete the octet around the boron.
h.
H
2
O
2
There are 14 valence electrons and an O-O bond. There are no
formal charges.
H
O O H
HCO
3
-
i.
There are 24 valence electrons involved. The hydrogen is
attached to an oxygen, not to carbon.
O
O
H
O C
O
(-1)
or
H
O
C
O
(-1)
The indicated oxygen has a formal charge: 6 - (6 + 1) = -1. All
other atoms are formally neutral.
1.46
There are 18 valence electrons (6 from each of the oxygens, 5 from the nitrogen, and 1
from the negative charge).
-1
O N
O
O
N O
or
-1
O
N
O
O
N
O
The negative charge in each contributor is on the singly bonded oxygen [6 - (6 + 1) =
-1. The other oxygen and the nitrogen have no formal charge. In the resonance hybrid,
the negative charge is spread equally over the two oxygens; the charge on each oxygen
is -1/2.
1.47
Each atom in both structures has a complete valence shell of electrons. There are no
formal charges in the first structure, but in the second structure, the oxygen is formally
positive and the carbon is formally negative.
+1
HOC
H
3
HOC
H
3
C
C
C
C
H
H
H
-1
H
