Lecture Notes Alan D. Earhart Southeast Community College Lincoln, NE Chapter 6 Ionic Bonds and Some Main-Group Chemistry John E. McMurry Robert C. Fay CHEMISTRY Fifth Edition Copyright © 2008 Pearson Prentice Hall, Inc.

Chapter 6/2 Ions and Their Electron Configurations + 3 e e e e e e - N: O: F: Na: Mg: Al: 1s 2 2s 2 2p 3 1s 2 2s 2 2p 4 1s 2 2s 2 2p 5 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 3s 2 1s 2 2s 2 2p 6 3s 2 3p 1 N 3- : O 2- : F 1- : Ne: Na 1+ : Mg 2+ : Al 3+ : 1s 2 2s 2 2p 6 IonsAtoms

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/3 Ions and Their Electron Configurations

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/4 Ions and Their Electron Configurations - 2 e e - Fe: [Ar] 4s 2 3d 6 Fe 2+ : Fe 3+ : [Ar] 3d 6 [Ar] 3d 5 IonsAtoms

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/5 Ionic Radii

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/6 Ionic Radii

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/7 Ionization Energy Ionization Energy (E i ): The amount of energy necessary to remove the highest-energy electron from an isolated neutral atom in the gaseous state.

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/8 Ionization Energy

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/9 Ionization Energy Boron has a lower E i due to a smaller Z eff (shielding by the 2s electrons)

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/10 Ionization Energy Oxygen has a lower E i since the first electron is removed from a filled orbital

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/11 Higher Ionization Energies M 3+ + e - M 2+ + energy M 1+ + e - M + energy M 2+ + e - M 1+ + energy

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/12 Electron Affinity Electron Affinity (E ea ): The energy released when a neutral atom gains an electron to form an anion.

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/13 Ionic Bonds and the Formation of Ionic Solids Na 1+ Na 1s 2 2s 2 2p 6 Cl+ 1s 2 2s 2 2p 6 3s 2 3p 6 3s13s1 3p53p5 1s 2 2s 2 2p 6 1s 2 2s 2 2p 6 3s 2 Cl 1-

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/14

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/15 Ionic Bonds and the Formation of Ionic Solids Born-Haber Cycle

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/16 Ionic Bonds and the Formation of Ionic Solids Born-Haber Cycle Step 2:Cl(g)Cl 2 (g)+122 kJ/mol Step 5: NaCl(s)Na(s) + Cl 2 (g)-411 kJ/mol 2 1 Step 1:Na(g)Na(s) kJ/mol Step 3:Na 1+ (g) + e - Na(g) kJ/mol Step 4:Cl 1- (g)Cl(g) + e kJ/mol NaCl(s)Na 1+ (g) + Cl 1- (g)-787 kJ/mol 2 1

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/17 Lattice Energies in Ionic Solids Lattice Energy (U): The amount of energy that must be supplied to break up an ionic solid into individual gaseous ions.

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/18 The Octet Rule Octet Rule: Main-group elements tend to undergo reactions that leave them with eight outer-shell electrons.

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/19 The Octet Rule Metals tend to have low E i and low E ea. They tend to lose one or more electrons. Nonmetals tend to have high E i and high E ea. They tend to gain one or more electrons. Octet Rule: Main-group elements tend to undergo reactions that leave them with eight outer-shell electrons.

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/20 The Octet Rule

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/21 Chemistry of the Group 1A Elements: Alkali Metals Good conductors of electricity Relatively soft Very reactive Occur only in salts Powerful reducing agents Metallic Bright, silvery Malleable

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/22 Chemistry of the Group 1A Elements: Alkali Metals Production 2Na(l) + Cl 2 (g)2NaCl(l) Electrolysis in CaCl °C 2Li(l) + Cl 2 (g)2LiCl(l) Electrolysis in KCl 450 °C

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/23 Chemistry of the Group 1A Elements: Alkali Metals Production 2Cs(g) + CaCl 2 (l)2CsCl(l) + Ca(l) 750 °C K(g) + NaCl(l)KCl(l) + Na(l) 850 °C 2Rb(g) + CaCl 2 (l)2RbCl(l) + Ca(l) 750 °C

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/24 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Hydrogen and Nitrogen X = F, Cl, Br, or I M = Li, Na, K, Rb, or Cs Reaction with Halogens 2MX(s)2MX(s)2M(s) + X 2 M = Li, Na, K, Rb, or Cs 2Li 3 N(s)6Li(s) + N 2 (g) Heat 2MH(s)2M(s) + H 2 (g) Heat

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/25 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Oxygen KO 2 (s)K(s) + O 2 (g)superoxide 2Li 2 O(s)4Li(s) + O 2 (g)oxide Na 2 O 2 (s)2Na(s) + O 2 (g)peroxide

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/26 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Ammonia 2M 1+ (soln) + 2NH 2 1- (soln) + H 2 (g)2M(s) + 2NH 3 (l) M = Li, Na, K, Rb, or Cs Reaction with Water 2M 1+ (aq) + 2OH 1- (aq) + H 2 (g)2M(s) + 2H 2 O(l) M = Li, Na, K, Rb, or Cs

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/27 Chemistry of the Group 2A Elements: Alkaline Earth Metals Relatively soft (harder than 1a) Not as reactive as 1a Occur only in salts Powerful reducing agents Metallic Bright, silvery

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/28 Chemistry of the Group 2A Elements: Alkaline Earth Metals Production Mg(l) + Cl 2 (g)MgCl 2 (l) Electrolysis 3M(l) + Al 2 O 3 (s)3MO(l) + 2Al(l) High Temp Be(l) + MgF 2 (l)BeF 2 (l) + Mg(l) 1300 °C M = Ca, Sr, or Ba

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/29 Chemistry of the Group 2A Elements: Alkaline Earth Metals Reaction with Oxygen 2MO2MO2M + O 2 M = Be, Mg, Ca, Sr, or Ba X = F, Cl, Br, or I Reaction with Halogens MX2MX2 M + X 2 M = Be, Mg, Ca, Sr, or Ba

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/30 Chemistry of the Group 2A Elements: Alkaline Earth Metals Reaction with Water M 2+ (aq) + 2OH 1- (aq) + H 2 (g)M(s) + 2H 2 O(l) M = Mg, Ca, Sr, or Ba

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/31 Chemistry of the Group 3A Elements: Aluminum Reacts well with oxygen (forms an oxide coating) Does not react well with water due to the oxide coating Found in many minerals Metallic Bright, silvery Good conductor of electricity

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/32 Chemistry of the Group 3A Elements: Aluminum Production 4Al(l) + 3O 2 (g)2Al 2 O 3 (soln) 980 °C Electrolysis in Na 3 AlF 6 Reaction with Halogens 2AlX 3 2Al + 3X 2 X = F, Cl, Br, or I

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/33 Chemistry of the Group 3A Elements: Aluminum Reaction with Nitrogen 2AlN2Al + N 2 Reaction with Oxygen 2Al 2 O 3 4Al + 3O 2

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/34 Chemistry of the Group 7A Elements: Halogens Very reactive Occur only in salts and minerals Powerful oxidizing agents Nonmetals Exist as diatomics in elemental form

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/35 Chemistry of the Group 7A Elements: Halogens Production 2Na(l) + Cl 2 (g)2NaCl(l) 100 °C Electrolysis H 2 (g) + F 2 (g)2HF(l) 100 °C Electrolysis I 2 (s) + 2Cl 1- (aq)2 I 1- (aq) + Cl 2 (g) Br 2 (l) + 2Cl 1- (aq)2Br 1- (aq) + Cl 2 (g)

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/36 Chemistry of the Group 7A Elements: Halogens X = F, Cl, Br, or I Reaction with Other Halogens 2BrF(g)Br 2 (l) + F 2 (g) X = F, Cl, Br, or I Reaction with Metals 2MXn2MXn 2M + nX 2 M = Metal Reaction with Hydrogen 2HX(g)H 2 (g) + X 2 2 I Cl(s) I 2 (g) + Cl 2 (g)

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/37 Chemistry of the Group 8A Elements: Noble Gases Very unreactive Occur naturally as atomic gases Colorless and odorless Nonmetals

Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 6/38 Chemistry of the Group 8A Elements: Noble Gases XeF 6 (s)Xe(g) + 3F 2 (g) Reactions XeF 2 (s)Xe(g) + F 2 (g) XeF 4 (s)Xe(g) + 2F 2 (g)