TOPIC 5. ORGANIC REACTIONS: ACIDS AND BASES (Chapter 3) Lect Topics Reading L13 CLASSIFYING REACTIONS Substitution Elimination Addition Rearrangement A Preview of Reactivity Practical Aspects of Running a Reaction 3.1 Reactions and Their Mechanisms WHAT IS A MECHANISM? Electrophiles and Nucleophiles CURVED ARROWS Polarity and Heterolytic Bond Cleavage 3.4 The Use of Curved Arrows in Illustrating Reactions BOND MAKING AND BOND BREAKING STEPS Heterolytic Bond Cleavage Steps 3.3 Heterolysis of Bonds to Carbon: Carbocations and Carbanions L14 ACID-BASE REACTIONS Definitions pKa and Acid Strength Species that can act as an Acid and as a Base Predicting Equilibrium Constants 3.2 Acid – Base Reactions 3.6 Predicting the Outcome of Acid – Base Reactions THE STRENGTH OF ACIDS AND BASES pKa values 3.5 The Strength of Acids and Bases: Ka and pKa, STRUCTURE-ACIDITY RELATIONSHIPS Acidity: Across a Row in the Periodic Table Acidity: Down a Column of the Periodic Table The effect of Hybridization The effect of Resonance 3.7 The Relationship Between Structure and Acidity 3.10 The Acidity of Carboxylic Acids ORGANIC BASES The effect of Structure on Basicity 3.12 Organic Compounds as Bases ACID-BASE REACTIONS IN NON-AQUEOUS MEDIA 3.11 The Effect of the Solvent on Acidity 3.14 Acids and Bases in Nonaqueous Solutions continuedL15 PRACTICAL APPLICATIONS OF ACID-BASE CHEMISTRY Separation of Neutral, Acidic and Basic Compounds Provide Greater Water-solubility to Drugs Catalysis of Reactions ENERGY CHANGES AND EQUILIBRIA: THERMODYNAMICS Equilibrium Enthalpy Calculating Heats of Reaction, ΔH Relationship Between Keq and ΔG° 3.8 Energy Changes 3.9 The Relationship Between the Equilibrium Constant and the Standard Free-Energy Change KINETICS Transition State Theory: Energy-Reaction Coordinate Diagram for a One-Step Reaction Energy-Reaction Coordinate Diagram for a Two-Step Reaction A MULTISTEP MECHANISM IN WHICH THE FIRST STEP IS AN ACID-BASE REACTION Substitution of tert-Butyl Alcohol 3.13 A Mechanism for an Organic Reaction NOT COVERED: 3.15 Acid-Base Reactions and the Synthesis of Deuterium- and Tritium-labeled