Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Copyright © 2010 Pearson Prentice Hall, Inc. Copyright © 2010 Pearson Prentice Hall, Inc.

Molecules, Ions, and Chemical Bonds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Molecules, Ions, and Chemical Bonds Covalent Bond: A bond that results from the sharing of electrons between atoms. Copyright © 2010 Pearson Prentice Hall, Inc.

Molecules, Ions, and Chemical Bonds – Models Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Molecules, Ions, and Chemical Bonds – Models For binary compounds, a covalent bond is often formed from a nonmetal bonded to a metal. Copyright © 2010 Pearson Prentice Hall, Inc.

Molecules, Ions, and Chemical Bonds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Molecules, Ions, and Chemical Bonds Ion: A charged particle. Cation: A positively charged particle. Metals tend to form cations. Anion: A negatively charged particle. Nonmetals tend to form anions. Ionic Bond: A transfer of one or more electrons from one atom to another. An electrostatic attraction between charged particles. Typically a metal bonded to a nonmetal. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chlorine gas Sodium chloride: an ionic compound Sodium - very reactive in water! Chlorine gas - can kill someone (Fritz Haber, WWI). Sodium chloride - preservative, common food additive. Sodium metal Copyright © 2010 Pearson Prentice Hall, Inc.

Molecules, Ions, and Chemical Bonds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Molecules, Ions, and Chemical Bonds In the formation of sodium chloride, one electron is transferred from the sodium atom to a chlorine atom. 11 protons 11 electrons 17 protons 17 electrons 1 2 Na1+ + Cl1- Na + Cl2 Monatomic ions have a different number of electrons than their corresponding atoms. 11 protons 10 electrons 17 protons 18 electrons Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Copyright © 2010 Pearson Prentice Hall, Inc.

Electron Configurations of Ions Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Electron Configurations of Ions Atoms Ions - e- Na: Cl: 1s2 2s2 2p6 3s1 1s2 2s2 2p6 3s1 3p5 Na1+: Cl1-: 1s2 2s2 2p6 1s2 2s2 2p6 3s1 3p6 + e- Copyright © 2010 Pearson Prentice Hall, Inc.

Electron Configurations of Ions Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Electron Configurations of Ions Copyright © 2010 Pearson Prentice Hall, Inc.

Electron Configurations of Ions Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Electron Configurations of Ions Atoms Ions -2 e- Fe: [Ar] 4s2 3d6 Fe2+: Fe3+: [Ar] 3d6 [Ar] 3d5 -3 e- Aufbau principle for ions is based on the energy ordering for the resulting ions. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionic Radii Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionic Radii Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionization Energy Ionization Energy (Ei): The amount of energy necessary to remove the highest-energy electron from an isolated neutral atom in the gaseous state. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionization Energy Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionization Energy Boron has a lower Ei due to a smaller Zeff (shielding by the 2s electrons) Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionization Energy Oxygen has a lower Ei since the first electron is removed from a filled orbital Copyright © 2010 Pearson Prentice Hall, Inc.

Rationale for higher Ei Values Be (1s22s2) Ei = 899.4 kJ/mol B (1s22s22p1) Ei = 800.6 kJ/mol N (1s22s22p3) Ei = 1402.3 kJ/mol O (1s22s22p4) Ei = 1313.9 kJ/mol Copyright © 2010 Pearson Prentice Hall, Inc.

Higher Ionization Energy Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Higher Ionization Energy M1+ + e- M + energy M2+ + e- M1+ + energy M3+ + e- M2+ + energy Copyright © 2010 Pearson Prentice Hall, Inc.

Copyright © 2010 Pearson Prentice Hall, Inc. Why ? Na = (1s22s22p63s1)  [Ne]  (1s22s22p5) E1 moves to [Ne] config. E2 moves away from [Ne] config. Mg = (1s22s22p63s2)  (1s22s22p63s1)  [Ne] E1 moves to ½ filled s orbital config. E2 moves to [Ne] config. Al = (1s22s22p63s23p1)  [Ne] (1s22s22p63s1) E1 moves to filled s orbital config. E2 moves to ½ filled s orbital E3 moves to [Ne] config. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry Electron Affinity 4/23/2017 Electron Affinity (Eea): The energy released when a neutral atom gains an electron to form an anion. Books use different conventions. The one this book uses assigns a negative sign to electron affinity. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 The Octet Rule Octet Rule: Main-group elements tend to undergo reactions that leave them with eight outer-shell electrons. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 The Octet Rule Octet Rule: Main-group elements tend to undergo reactions that leave them with eight outer-shell electrons. Metals tend to have low Ei and low Eea. They tend to lose one or more electrons. Nonmetals tend to have high Ei and high Eea. They tend to gain one or more electrons. Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 A Born-Haber cycle for the formation of NaCl. Copyright © 2010 Pearson Prentice Hall, Inc.

Ionic Bonds and the Formation of Ionic Solids Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Ionic Bonds and the Formation of Ionic Solids Born-Haber Cycle Step 1: Na(g) Na(s) +107.3 kJ/mol 2 1 Step 2: Cl(g) Cl2(g) +122 kJ/mol Step 3: Na1+(g) + e- Na(g) +495.8 kJ/mol Step 1: sublimation energy Step 2: bond dissociation energy Step 3: ionization energy Step 4: -(electron affinity) Step 5: lattice energy Step 4: Cl1-(g) Cl(g) + e- -348.6 kJ/mol Step 5: NaCl(s) Na1+(g) + Cl1-(g) -787 kJ/mol 2 1 NaCl(s) Na(s) + Cl2(g) -411 kJ/mol Copyright © 2010 Pearson Prentice Hall, Inc.

Lattice Energies in Ionic Solids Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 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 © 2010 Pearson Prentice Hall, Inc.

Naming Ionic Compounds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Naming Ionic Compounds Cation Charges for Typical Main-Group Ions 1+ 2+ 3+ Metals tend to form cations. Note some in 3A and 4A with multiple charges. Copyright © 2010 Pearson Prentice Hall, Inc.

Naming Ionic Compounds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Naming Ionic Compounds Anion Charges for Typical Main-Group Ions 3- 2- 1- Nonmetals tend to form anions. Noble gases do not naturally form ions in this sense. Copyright © 2010 Pearson Prentice Hall, Inc.

Naming Ionic Compounds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Naming Ionic Compounds Some transition metals form more than one cation Copyright © 2010 Pearson Prentice Hall, Inc.

Naming Ionic Compounds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Naming Ionic Compounds Ionic Compound: A neutral compound in which the total number of positive charges must equal the total number of negative charges. Binary Ionic Compounds sodium chloride: Na1+ Cl1- NaCl magnesium oxide: Mg2+ O2- MgO aluminum sulfide: Al3+ S2- Al2S3 Copyright © 2010 Pearson Prentice Hall, Inc.

Naming Ionic Compounds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Naming Ionic Compounds Use Roman numerals in parentheses to indicate the charge on metals that form more than one kind of cation. Binary Ionic Compounds iron(III) oxide: Fe3+ O2- Fe2O3 tin(II) chloride: Sn2+ Cl1- SnCl2 lead(II) fluoride: Pb2+ F1- PbF2 Copyright © 2010 Pearson Prentice Hall, Inc.

Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Polyatomic ions are covalently bonded atoms with a net charge. Copyright © 2010 Pearson Prentice Hall, Inc.

Naming Ionic Compounds Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Naming Ionic Compounds Polyatomic Ionic Compounds sodium hydroxide: Na1+ OH1- NaOH magnesium carbonate: Mg2+ CO32- MgCO3 sodium carbonate: Na1+ CO32- Na2CO3 iron(II) hydroxide: Fe2+ OH1- Fe(OH)2 Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 1A Elements: Alkali Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 1A Elements: Alkali Metals Metallic Bright, silvery Malleable Relatively soft Good conductors of electricity Very reactive Occur only in salts A book that effortlessly ties world history together via salt (NaCl) is Kurlansky, Mark; Salt: A World History; Penguin Books; 2002. Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 1A Elements: Alkali Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Halogens 2MX(s) 2M(s) + X2 M = Li, Na, K, Rb, or Cs X = F, Cl, Br, or I Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 1A Elements: Alkali Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Oxygen 2Li2O(s) 4Li(s) + O2(g) oxide Na2O2(s) 2Na(s) + O2(g) peroxide KO2(s) K(s) + O2(g) superoxide Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 1A Elements: Alkali Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Water 2M1+(aq) + 2OH1-(aq) + H2(g) 2M(s) + 2H2O(l) M = Li, Na, K, Rb, or Cs Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 1A Elements: Alkali Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 1A Elements: Alkali Metals Reaction with Ammonia 2M1+(soln) + 2NH21-(soln) + H2(g) 2M(s) + 2NH3(l) M = Li, Na, K, Rb, or Cs Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 2A Elements: Alkaline Earth Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 2A Elements: Alkaline Earth Metals Metallic Bright, silvery Occur only in salts Relatively soft (harder than 1a) Not as reactive as 1a Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 2A Elements: Alkaline Earth Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 2A Elements: Alkaline Earth Metals Reaction with Halogens MX2 M + X2 M = Be, Mg, Ca, Sr, or Ba X = F, Cl, Br, or I Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 2A Elements: Alkaline Earth Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 2A Elements: Alkaline Earth Metals Reaction with Oxygen 2MO 2M + O2 M = Be, Mg, Ca, Sr, or Ba Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 2A Elements: Alkaline Earth Metals Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 2A Elements: Alkaline Earth Metals Reaction with Water M2+(aq) + 2OH1-(aq) + H2(g) M(s) + 2H2O(l) M = Mg, Ca, Sr, or Ba Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 7A Elements: Halogens Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 7A Elements: Halogens Nonmetals Exist as diatomics in elemental form Very reactive Occur only in salts and minerals “Halogen” is Greek for “salt former.” Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 7A Elements: Halogens Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 7A Elements: Halogens Reaction with Metals 2MXn 2M + nX2 M = Metal X = F, Cl, Br, or I Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 7A Elements: Halogens Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 7A Elements: Halogens Reaction with Hydrogen 2HX(g) H2(g) + X2 X = F, Cl, Br, or I Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 8A Elements: Noble Gases Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 8A Elements: Noble Gases Previously called “rare” gases. Argon makes up almost 1% of dry air volume. Not so rare! Previously called “inert” gases. Many compounds of Kr and Xe are now known. Not so inert! Colorless and odorless Nonmetals Very unreactive Occur naturally as atomic gases Copyright © 2010 Pearson Prentice Hall, Inc.

Chemistry of the Group 8A Elements: Noble Gases Chapter 4: Ionic Bonds and Some Main-Group Chemistry 4/23/2017 Chemistry of the Group 8A Elements: Noble Gases Reactions XeF2(s) Xe(g) + F2(g) XeF4(s) Xe(g) + 2F2(g) XeF6(s) Xe(g) + 3F2(g) Copyright © 2010 Pearson Prentice Hall, Inc.