1. General Chemistry Review
Chapters 1 & 2
General Chemistry Review
Electronic Structure
and
Bonding
Molecular
Representations

2. Molecular Representations
Klein: 2.1, 2.2, 2.6 5

3. Molecular Representations
Empirical Formula, Molecular Formula, Structure: (Lewis, Kekule, Condensed, Line), Visual Model: wireframe, stick, ball & stick, space filling, electrostatic, energy surface

5. Draw bond-line structures for each of the four molecules.
ketone 1.
aldehyde 2.
carboxylic acid 3.
ester (carboxylic acid ester)
Figure Number: T05UN
Title: Table 1.5 An oxygen doubly bonded to a carbon.
Caption: Condensed structures can be written in different forms
Notes: The condensed structures are simplified by omitting some or all of the covalent bonds (lines and dots) and listing atoms bonded to a particular carbon (or nitrogen, or oxygen) next to it with a subscript to indicate the number of such atoms. 4.

6. Introduction to Organic Functions (Functional Groups) (Klein 2.3)
ketone 1.
aldehyde 2.
carboxylic acid 3.
ester (carboxylic acid ester)
Figure Number: T05UN
Title: Table 1.5 An oxygen doubly bonded to a carbon.
Caption: Condensed structures can be written in different forms
Notes: The condensed structures are simplified by omitting some or all of the covalent bonds (lines and dots) and listing atoms bonded to a particular carbon (or nitrogen, or oxygen) next to it with a subscript to indicate the number of such atoms. 4.
Worksheet 3: Organic Functional Groups (2 Sudoku)
Worksheet 4: Functions, Polarity, Formal Charge 6

7. Question 2.1 The molecular formula of morpholine is: A) C2HNO B) C4HNO
C) C4H4NO
D) C4H5NO
E) C4H9NO

8. Question 2.2
The respective number of bonded pairs of electrons and of unshared pairs of electrons in morpholine is:
A) 7, 0
B) 7, 1
C) 15, 0
D) 15, 1
E) , 3

9. Formulas & Kekulé / Condensed / Bond-Line Structures / Drawings
Molecular formula?
Empirical Formula?
C7H16O
C7H16O
Bond-Line Structure?
Figure Number: T05UN
Title: Table 1.5 Groups bonded to the far right carbon.
Caption:
Notes:

10. Question 2.3 The bond-line representation for (CH3)2CHCH2CH2CHBrCH3 is
A) B)
C) D)

11. Question 2.4
Select the best condensed structural formula for the following bond-line structure:
(CH3)2CHCH2COHOHCOH
CH3CH3CHCH2C(OH)2CHO
(CH3)2CHCH2C(OH)2CHO
(CH3)2CHCH2C(OH)2COH
CH3CHCH3CH2C(OH)2CHO

12. Line Drawing and Ball & Stick
8.16 Å (0.816 nm)

13. Question 2.5 While on-line, examine the jmol-structure on the left.
Which one of the formulas or structural renderings that follow is correct? 13

14. Worksheet 2: Structures, Formulas & Orbitals

15. Question 2.6
How many constitutional alcohol isomers have the molecular formula C4H10O?
A) two
B) three
C) four
D) five
E) six
SEE:

16. Worksheet: Organic Molecules 1
More Molecular Representations
Empirical Formula, Molecular Formula, Structure: (Lewis, Kekule, Condensed, Line), Visual Model: wireframe, stick, ball & stick, space filling, electrostatic, energy surface
Worksheet: Organic Molecules 1

17. Very Large Molecules:DNA
Views & Algorithms
10.85 Å
10.85 Å
15-23
Title:
Base Pairs
Caption:
Representation of the base pairings of thymine and adenine, and cytosine and guanine, in line as well as ball-and-stick models.
Notes:
Base pairs occur through hydrogen bonding.
Several formats are commonly used but all rely on plotting atoms in 3 dimensional space; .pdb is one of the most popular.

18. B-DNA: Size, Shape & Self Assembly
Very Large Molecules
B-DNA: Size, Shape & Self Assembly
46 Å
Rosalind Franklin’s
Photo
12 base sequence
( )

19. Atomic Orbitals Valence Bond theory Molecular Orbital Theory
Klein: 1.6 – 1.9 5

20. Atomic Orbitals
Experimental data shows that electrons, like light and photons, behave as BOTH particles and waves.
Orbital theory that was developed from this observation offers the ability to make fairly accurate predictions.
Like a lake’s wave, an electron’s wavefunction can be (+), (-), or ZERO.

21. Atomic Orbitals
Orbitals are mathematically derived from wavefunctions. (Solutions for values of ℓ.) Remember the four q.n.: n (principal), ℓ (orbital), mℓ (magnetic), ms (spin)
Orbital regions can be (-), (+), or ZERO based on mℓ .
In the example on the right of a p-orbital, ℓ = 1, there are three possible values for mℓ . The point where mℓ = 0 is referred to as a Node or nodal plane.
The sign of mℓ is important in considering orbital overlap and bond formation.

22. Atomic Orbitals
s and p orbitals

23. Atomic Orbitals Molecular Orbital (MO)
Atomic orbitals mix to form molecular orbitals
The total number of molecular orbitals (bonding + non- and anti bonding orbitals) equal the total number of atomic orbitals
s bond is formed by overlapping of two s orbitals

24. MO & Valence Bond Theories
A bond occurs when certain atomic orbitals overlap. These overlapping orbitals are like waves.
Only constructive interference results in a bond.

26. In-phase overlap of s atomic orbitals form a bonding MO (no node);
Out-of-phase overlap forms an antibonding MO (has node)
A single bond is a s bond with a bond order of 1.

27. A sigma bond (s) is also formed by end-on overlap
of two p orbitals
Double bonds have 1 s and 1 p bond with a bond order of 2.
A p bond is weaker than a s bond.
A double bond is shorter and stronger than a single bond.

28. Molecular Orbital Theory
Consider the MOs for CHBr3:
There are many areas of atomic orbital overlap.
Notice how the MOs extend over the entire molecule.
Each image represents ONE orbital, which depending on its energy can be bonding (lowest) or non-bonding (higher) or anti-bonding (highest).

29. Pi bond (p) is formed by sideways overlap of two parallel
p orbitals

30. Mixing Atomic Orbitals
Hybridization of s and p orbitals 30

31. Single Bonds (Methane)
Hybridization of s and p atomic orbitals:

32. The atomic orbitals used in bond formation determine the bond angles
Tetrahedral bond angle: 109.5°
Electron pairs spread themselves into space as far from
each other as possible

33. Hybrid Orbitals of Ethane
Practice:
CONCEPTUAL CHECKPOINT 1.19

34. Bonding in Ethene: A Double Bond
Double bonds have 1 p and 1 s bond.
A double bond is shorter and stronger than a single bond.
Practice:
CONCEPTUAL CHECKPOINT 1.20

35. Ethene: Molecular Orbitals
MO theory provides a similar theoretical picture:
NOTE: the red and blue regions are part of the same orbital.

36. An sp2-Hybridized Carbon
The bond angle in the sp2 carbon is 120°
The sp2 carbon is the trigonal planar carbon

37. Ethyne: A Triple Bond sp-Hybridized Carbon
A triple bond consists of one s bond and two p bonds with a bond order of 3.
Triple bonds are shorter and stronger than double bonds
There is a bond angle of the sp carbon: 180°

38. Question 2.7
What is the molecular shape of each of the carbons of tetrachloro ethene (Cl2CCCl2)?
A) tetrahedral
B) bent
C) trigonal planar
D) linear
E) trigonal pyramidal

39. http://chemconnections.org//organic/Movies Org Flash/hybridization.swf

40. Summary A p bond is weaker than a s bond
The greater the electron density in the region of orbital
overlap, the stronger is the bond
The more s character, the shorter and stronger is the
bond
The more s character, the larger is the bond angle

41. Hybridization & Bond Strength
Being able to explain the different strengths and lengths: CONCEPTUAL CHECKPOINT 1.24.

42. Reactive Carbon Atoms
Klein: 2.4 5

43. Reactive Intermediates
Carbocation

44. Reactive Intermediates
Radical

45. Reactive Intermediates
Carbanion