Chapter 8 Covalent Bonding 8.1 Molecular Compounds 8.2 The Nature of Covalent Bonding 8.3 Bonding Theories 8.4 Polar Bonds and Molecules Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Molecules and Molecular Compounds Do Now (Part I): Classify as ionic or covalent Sodium Chloride, NaCl Methane, CH4 Oxygen, O2 Ammonia, NH3 Magnesium Oxide, MgO Barium Iodide, BaI2 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Do Now (Part II): Write formulas for Write names for Magnesium Sulfide Carbon Dioxide Sodium Phosphite Copper(II) Nitrite Write names for 5. NaClO3 6. N2O5 7. K2CrO4 8. SnO2 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Do Now: Write formulas for Write names for Magnesium Sulfide - MgS Carbon Dioxide - CO2 Sodium Phosphite – Na3PO3 Copper(II) Nitrite – Cu(NO2)2 Write names for 5. NaClO3 – Sodium Chlorate 6. N2O5 – Dinitrogen Pentoxide 7. K2CrO4 – Potassium Chromate 8. SnO2 – Tin(IV) Oxide Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Molecules and Molecular Compounds Covalent bond: a bond in which atoms are held together through the sharing of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Molecules and Molecular Compounds Molecule: neutral group of atoms joined by covalent bonds H2O - water C4H10 - butane C7H5N3O6 – trinitrotoluene (TNT) Molecular formula - shows how many atoms of each element a molecule contains Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Do Now: Write formulas for Write names for Diphosphorous Pentoxide Calcium Chloride Sodium Phosphate Iron(II) Sulfate Write names for 5. Na2CO3 6. PF3 7. AlCl3 8. CoBr2 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Do Now: Write formulas for Write names for Diphosphorous Pentoxide – P2O5 Calcium Chloride - CaCl2 Sodium Phosphate – Na3PO4 Iron(II) Sulfate – FeSO4 Write names for 5. Na2CO3 – Sodium Carbonate 6. PF3 – Phosphorous Trifluoride 7. AlCl3 – Aluminum Chloride 8. CoBr2 – Cobalt(II) Bromide Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding How many total valence electrons are in the following molecules? SiO2 HCl H2O HCN Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Single Covalent Bond: atoms held together by sharing one pair of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Structural Formula: represents covalent bonds as dashes and shows arrangement of covalently bonded atoms. H:H H-H Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Double Covalent Bond: bond that involves two shared pairs of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Triple Covalent Bond: a bond formed by sharing three pairs of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Bond Dissociation Energies Bond Dissociation Energy: energy required to break the bond between two covalently bonded atoms. Bond Bond Dissociation Energy (kJ/mol) Bond Length (pm) C C 347 154 C = C 657 133 908 121 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Molecules and Molecular Compounds Diatomic molecule - molecule that contains two atoms. HOFBrINCl Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Draw Lewis Structures for: SiO2 HCl H2O HCN Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Drawing Lewis Dot Structures: Determine # of valence e- Determine # of “octet” e- *Note*– Hydrogen gets 2 # bonds = (# valence e- - # octet e-) / 2 Arrange atoms with # bonds from step 3. Least electronegative element tends to be in the center Hydrogen & halogens - bond 1 time (on outside) Group 6A - bond 2 times Group 5A - bond 3 times Carbon - bond 4 times Add e- until all atoms have correct number of e- Recheck! Make sure have correct # of e-! Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Coordinate Covalent Bonds Coordinate Covalent Bond: bond in which one atom contributes both bonding electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Exceptions to the Octet Rule Total number of valence electrons is an odd number. 2. Boron wants 6 electrons for neutral molecules. 3. Phosphorus and sulfur expand the octet to 10 or 12 electrons. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Ozone has two possible electron dot structures. Resonance Resonance structures: structures that occur when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule or ion. Ozone has two possible electron dot structures. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.