Frequency modulation basic and fundamentals. It includes transmissions answer key to different FM problems. Please bear in mind that it must not be a substitute to traditional learning. Use …Full description
Descripción completa
Naruto D20, D20 Modern
A level chemistry
moocFull description
Magnetic Resonance Imaging
nuclearDeskripsi lengkap
igre
i amkmekfklm edef
aa
Deskripsi lengkap
Resonance study material
Full description
Deskripsi lengkap
reso
study materialFull description
FAGfgasfg
mri
CHAPTER SEVEN Resonance Structure 7.1
Bond length is defined as the distance between the nuclei of two covalently bonded atoms in a molecule. Resonance means the use of two or more Lewis structures to represent a particular molecule. Resonance structure is one of two or more Lewis structures for a single molecule that cannot be represented accurately by only one Lewis structure. A rule for writing resonance structure is that the positions of electrons, but not those of atoms, can be rearranged in different resonance structures. Also, note that although it is more accurate to show all the resonance structures of an ion or a compound, we often use only one Lewis structure for simplicity.
7.2
It is not possible to trap a resonance structure of a compound for study. An individual resonance structure is a partial representation of the electron distribution in a molecule. The true electronic distribution is a cross of all valid resonance structures.
7.3
The resonance structures are:
O H
-
O H
C
C O
O
O
H C
O
H
+
-
N O
O
H
-
+
C
N
H
-
-
+
C
H
7.4
-
-
N
H
O
O
-
−
The Lewis structure for ClO3 is shown below. O
(−1)
O
Cl
(−1)
O
(+1)
We can draw two more equivalent Lewis structures with the double bond between Cl and a different oxygen atom. The resonance structures with formal charges are as follows: (−1)
(−1)
O O
Cl
(−1)
O
O
Cl
(+1)
7.5
H
O
O (−1)
(−1)
(−1)
O
O
Cl
O
(+1)
(+1)
The structures of the most important resonance forms are:
N
+
N
N
−
− H
N
+
N
N
H
+
N
+
N
2− N
7.6
The structures of the most important resonance forms are: H
H (+1)
H
7.7
C
N
H
C
(+1)
N
N
−
−
C
−
O
N
C
2−
+
N
O
C
N
Three reasonable resonance structures with the formal charges indicated are (−1)
(+1)
N
7.9
N
(−1)
Three reasonable resonance structures for OCN are: O
7.8
(−1)
(+1)
N
O
N
N
(−2)
(−1)
O
(+1)
N
N
(+1)
O
A resonance structure is:
O
+
N
C
H
7.10 bond.
The rest of the molecule (in this problem, unidentified) would be attached at the end of the free
−
(a) 7.11
O
O
O
O
C
−
(b)
H
C
C
O
O
The resonance structures are: N
C
O
(b) −C
+ N
O
(a)
−
−
−
2−
N
C
O
C
+ N
O
2−
3−
N
C
+ O
C
+ N
+ O
In both cases, the most likely structure is on the left and the least likely structure is on the right. 7.12
(a) (−)
N
O
N
(+)
O
The first structure is the most important. Both N and O have formal charges of zero. In the second structure, the more electronegative oxygen atom has a formal charge of +1. Having a positive formal charge on an highly electronegative atom is not favorable. In addition, both
structures leave one atom with an incomplete octet. This cannot be avoided due to the odd number of electrons. (b)
It is not possible to draw a structure with a triple bond between N and O. N
O
Any structure drawn with a triple bond will lead to an expanded octet. Elements in the second row of the period table cannot exceed the octet rule.
