1. Figure: 01-02
Caption:
Figure 1-2
Graph and diagram of the 1s atomic orbital. The electron density is highest at the nucleus and drops off exponentially with increasing distance from the nucleus in any
direction.

2. Figure: 01-03
Caption:
Figure 1-3
The 2s orbital has a small region of high electron density close to the nucleus, but most of the electron density is farther from the nucleus, beyond a node, or region of zero electron density.

3. Figure: 01-04
Caption:
Figure 1-4
The 2p orbitals. There are three 2p orbitals, oriented at right angles to each other. Each is labeled according to its orientation along the x, y, or z axis.

4. sp3 hybridization tetrahedral geometry bond angle = Figure: 02-15
Caption:
Figure 2-15
Hybridization of an s orbital with all three p orbitals gives four sp3 hybrid orbitals with tetrahedral geometry and 109.5° bond angles.

5. sp3 hybridization of carbon in methane
tetrahedral
geometry
Figure: 02-16
Caption:
Figure 2-16
Methane has tetrahedral geometry, using four sp3 hybrid orbitals to form sigma bonds to the four hydrogen atoms.

6. sp2 hybridization trigonal geometry Figure: 02-14 Caption: Figure 2-14
Hybridization of an s orbital with two p orbitals gives a set of three sp2 hybrid orbitals. The bond angles associated with this trigonal structure are about 120°. The remaining p orbital is perpendicular to the plane of the three hybrid orbitals.

7. sp2 hybridization of carbon in ethylene (a.k.a. ethene)
trigonal
geometry
Figure: 02-17
Caption:
Figure 2-17
The carbon atoms in ethylene are sp2 hybridized, with trigonal bond angles of about 120°. All the carbon and hydrogen atoms lie in the same plane.

8. sp hybridization of carbon in acetylene (a.k.a. ethyne)
Figure: 02-18
Caption:
Figure 2-18
The carbon atoms in acetylene are sp hybridized, with linear (180°) bond angles. The triple bond contains one sigma bond and two perpendicular pi bonds.

10. Bronsted-Lowry Acid-Base Concept

11. Lewis Acid-Base Concept
Electron pair
donor
Electron pair
acceptor

12. General Acid-Base ReactionHA  
+ H2O
H3O A-
Ka =
[H3O+] [A-]
[HA]
pKa
= - log Ka

13. Ka pKa Figure: 01-07-042T1-5 Caption:
TABLE 1-5 Relative Strength of Some Common Organic and Inorganic Acids and Their Conjugate Bases

14. Electronegativity Effect on Acidity

15. (i.e., Size of Conjugate Base)
Size Effect on Acidity
(i.e., Size of Conjugate Base)

16. Resonance Effect on Acidity

17. H3PO4 H2PO4- + H+ HPO42- + H+ PO43- + H+  
Buffer Effect
Henderson-Hasselbalch Equation:
pH = pKa + log
[A-]
[HA]
The Henderson-Hasselbalch equation describes how the pH of a solution is governed by the pKa of the acid present and the logarithm of the ratio of the concentrations of the conjugate base and protonated form of the acid. If the pH is greater than the pKa of the acid, it will predominantly exist in it’s conjugate base form. If the pH is less than the pKa, the acid will exist predominantly in it’s protonated form.
Buffer Effect: The ability of a solution to resist a change in pH as H+ or HO- are added to it.
Buffer Capacity: The amount of H+ or HO- that can be absorbed before the pH begins to shift significantly. The buffer capacity of a solution is related to the total concentration of HA & A- in solution as well as the magnitude of the separation between the pH & pKa.
Of the many species capable of buffer action in biological systems, the most important biological buffers are H2PO4- (phosphate) and H2CO3/HCO3- (carbonate) due to their higher relative concentrations (i.e., greater buffer capacity).
Figure: UN
Caption:
Electronegativity.  A more electronegative element bears a negative charge more easily, giving a more stable conjugate base and a stronger acid. Electronegativities increase from left to right in the periodic table:
CO2 + H2O H2CO HCO H+  
Carbonate:
Phosphate:
H3PO H2PO4- + H HPO42- + H PO43- + H+  

18. Buffer Effect Phosphate Titration Curve Acetate Titration Curve PO43-
H3PO4
H2PO4- + H+  
H2PO4-
HPO42- + H+
HPO42-
PO43- + H+
Phosphate Titration Curve
PO43-
Acetate Titration Curve
CH3CO2H CH3CO H+  

19. Titration Curve for the
pKa’s of Some Amino Acids
Titration Curve for the
Amino Acid Histidine