04 BASIC CONCEPTS OF CHEMICAL BONDING

Information about 04 BASIC CONCEPTS OF CHEMICAL BONDING

Published on July 4, 2008

Author: cpesison

Source: authorstream.com

Content

Slide 1: Chapter 04 Basic Concepts Of Chemical Bonding Slide 2: Chemical Bonding – is the force of attraction between any two atoms in a compound. This attraction is the force that overcomes the repulsion of the positively charged nuclei Lewis Symbols Lewis Symbols (or Lewis Structures) – is a convenient way of representing atoms singly or in combination. Only the valence electrons are shown 4.1 Chemical Bonding Slide 3: Principal Type of Chemical Bonds: Ionic Bond - complete transfer of one or more electrons from one atom to another Covalent Bond – two atoms share electrons 4.1 Chemical Bonding Slide 4: Ionic Bonding Metal + Nonmetal Covalent Bonding - Nonmetal + Nonmetal 4.1 Chemical Bonding Slide 5: Ionic Bond – complete transfer of electrons Covalent Bond – sharing of electrons Polar Covalent Bond – a bond made up of unequally shared electron pairs. Non-polar Covalent Bond – a bond made up of equally shared electron pairs 4.1 Chemical Bonding Slide 6: Electronegativity Difference in Electronegativity (ΔEn) 4.1 Chemical Bonding Slide 7: Ionic Bond – complete transfer of electrons Covalent Bond – sharing of electrons Polar Covalent Bond – a bond made up of unequally shared electron pairs. Non-polar Covalent Bond – a bond made up of equally shared electron pairs 4.1 Chemical Bonding ENCl = 3.0 3.0 - 3.0 = 0 Non-Polar Covalent ENCl = 3.0 ENH = 2.1 3.0 – 2.1 = 0.9 Polar Covalent ENCl = 3.0 ENNa = 1.0 3.0 – 0.9 = 2.1 Ionic Slide 8: Electron-Dot Structures (Lewis Structures): A representation of an atom’s valence electrons by using dots and indicates by the placement of dots how the valence electrons are distributed in the molecule. 4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Slide 9:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Slide 10: Example 4.8 Draw the Lewis Structure of Carbon Dioxide (CO2) Example 4.9 Draw the Lewis Structure of Ammonia (NH3) Example 4.10 Draw the Lewis Structure of the ammonium ion (NH4+) Example 4.11 Draw the Lewis Structure of the sulfate ion (SO42-) Slide 11: Example 4.12 Draw the Lewis Structure of the acetate ion (CH3COO)- Example 4.13 Draw the possible resonance structures of the nitrate ion, NO3-, and represent them as a resonance hybrid. Slide 12: Example 4.14 Draw the Lewis structure of beryllium hydride, BeH2. Example 4.15 Draw the Lewis structure of phosphorus pentafluoride, PF5. Common Bonding Patterns : Common Bonding Patterns - Practice - Lewis Structures : Practice - Lewis Structures CO2 SeOF2 NO2-1 H3PO4 SO3-2 P2H4 Practice - Lewis Structures : Practice - Lewis Structures CO2 SeOF2 NO2-1 H3PO4 SO3-2 P2H4 16 e- 26 e- 18 e- 26 e- 32 e- 14 e- Slide 16: Lewis Structures and Formal Charges 4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Calculate the formal charge on each atom in O3. 6 - (2) - 6 = -1 6 - (4) - 4 = 0 6 - (6) - 2 = +1 Practice - Assign Formal Charges : Tro, Chemistry: A Molecular Approach 17 Practice - Assign Formal Charges CO2 SeOF2 NO2-1 H3PO4 SO3-2 P2H4 Practice - Assign Formal Charges : Tro, Chemistry: A Molecular Approach 18 Practice - Assign Formal Charges CO2 SeOF2 NO2-1 H3PO4 SO3-2 P2H4 all 0 -1 P = +1 rest 0 S = +1 Se = +1 -1 -1 all 0 -1 -1 -1 Slide 19: 4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Resonance Resonance – there is more than one Lewis structure for a molecule that differ only in the position of the electrons and they are called resonance structures. - the actual molecule is a combination of the resonance forms – a resonance hybrid- it does not resonate between the two forms, though we often draw it that way Practice - Identify Structures with Better or Equal Resonance Forms and Draw Them : Tro, Chemistry: A Molecular Approach 20 Practice - Identify Structures with Better or Equal Resonance Forms and Draw Them CO2 SeOF2 NO2-1 H3PO4 SO3-2 P2H4 all 0 -1 P = +1 S = +1 Se = +1 -1 -1 all 0 -1 -1 -1 Practice - Identify Structures with Better or Equal Resonance Forms and Draw Them : Tro, Chemistry: A Molecular Approach 21 Practice - Identify Structures with Better or Equal Resonance Forms and Draw Them CO2 SeOF2 NO2-1 H3PO4 SO3-2 P2H4 none -1 -1 -1 +1 all 0 +1 all 0 -1 none S = 0 in all res. forms Slide 22: Lewis Structures and Molecular Geometry; VSEPR Theory Valence Shell Electron Pair Repulsion Theory (VSEPR) “… electron pair arrange themselves so that they can be as far as possible from each other.” -Electrons in bonds and in lone pairs can be thought of as “charge clouds” that repel one another and stay as far apart as possible, this causing molecules to assume specific shapes. 4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Slide 23:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Two Charge Clouds Slide 24:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Three Charge Clouds Slide 25:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Four Charge Clouds Slide 26:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Four Charge Clouds Slide 27:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Five Charge Clouds Slide 28:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Five Charge Clouds Slide 29:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Six Charge Clouds Slide 30:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Six Charge Clouds Slide 31:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Slide 32:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Slide 33:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Slide 34: Lewis Structures and Polarity 4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions Polar Nonpolar Slide 35: Nonpolar Polar Nonpolar Polar Slide 36:  4.4 Drawing Lewis Structures of Molecules and Polyatomic Ions

Related presentations


Other presentations created by cpesison

Chem 110r 04 Stoichiometry
02. 01. 2009
0 views

Chem 110r 04 Stoichiometry

Chem 121 03 AMINO ACIDS
22. 11. 2008
0 views

Chem 121 03 AMINO ACIDS

CHEM 110r Introduction
13. 11. 2008
0 views

CHEM 110r Introduction

CHEM 121 01 INTRODUCTION
07. 11. 2008
0 views

CHEM 121 01 INTRODUCTION

Chem 120 Reaction of Alcohols
29. 09. 2008
0 views

Chem 120 Reaction of Alcohols

Chem 120 10.1 HYDROCARBONS
02. 09. 2008
0 views

Chem 120 10.1 HYDROCARBONS

Chem 110 04 Stoichiometry
16. 08. 2008
0 views

Chem 110 04 Stoichiometry