Chapter3 - Chapter 3 An Introduction to Organic Reactions:...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 3 An Introduction to Organic Reactions: Acids and Bases
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 3 2 Reactions and Their Mechanisms There are four general types of organic reactions Substitutions Additions Eliminations
Background image of page 2
Chapter 3 3 Rearrangements Cleavage of Covalent Bonds Homolysis Heterolysis
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 3 4 Heterolytic reactions almost always occur at polar bonds The reaction is often assisted by formation of a new bond to another molecule
Background image of page 4
Chapter 3 5 Introduction to Acid-Base Chemistry Brønsted-Lowry Definition of Acids and Bases Acid: a substance that can donate a proton Base: a substance that can accept a proton Example Hydrogen chloride is a very strong acid and essentially all hydrogen chloride molecules transfer their proton to water
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 3 6 Example Aqueous hydrogen chloride and aqueous sodium hydroxide are mixed The actual reaction is between hydronium and hydroxide ions
Background image of page 6
Chapter 3 7 Lewis Definition of Acids and Bases Lewis Acid: electron pair acceptor Lewis Base: electron pair donor Curved arrows show movement of electrons to form and break bonds
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 3 8 Opposite Charges Attract and React BF 3 and NH 3 react based on their relative electron densities BF 3 has substantial positive charge on the boron NH 3 has substantial negative charge localized at the lone pair
Background image of page 8
Chapter 3 9 Heterolysis of Bonds to Carbons: Carbanions and Carbocations Reaction can occur to give a carbocation or carbanion depending on the nature of Z Carbocations have only 6 valence electrons and a positive charge
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 3 10 Carbanions have 8 valence electrons and a negative charge Organic chemistry terms for Lewis acids and bases Electrophiles (“electron-loving” reagents ): seek electrons to obtain a stable valence shell of electrons Are electron-deficient themselves e.g. carbocations Nucleophiles (“nucleus-loving” reagents): seek a proton or some other positively charged center Are electron-rich themselves e.g. carbanions
Background image of page 10
Chapter 3 11 The Use of Curved Arrows in Illustrating Reactions Curved arrows show the flow of electrons in a reaction An arrow starts at a site of higher electron density (a covalent bond or unshared electron pair) and points to a site of electron deficiency Example: Mechanism of reaction of HCl and water
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 3 12 Strengths of Acids and Bases K a and pK a Acetic acid is a relatively weak acid and a 0.1M solution is only able to protonate water to the extent of about 1% The equilibrium equation for this reaction is:
Background image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 41

Chapter3 - Chapter 3 An Introduction to Organic Reactions:...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online