Guide for Chapters 8 & 6
Chapter 8 reminds us that we can learn about the nature of bonds by making certain measurements. Measured dipole moments can be correlated to bond type if we apply electronegativity concepts to the molecule. Measured bond energies can help us understand covalent bonding in chemical reactions. Measurements of IE, EA, and other properties can give us information about ionic lattice energies. Hess's Law, or the Law of Additivity of Heats of Reaction (in chapter 6), provides us a way to derive energy amounts that can't be measured directly in the lab. An understanding of the energy changes that take place in a reaction can help us learn more about the bonding within substances, and the properties that result from those bonds.
If you understand the material in chapter 8, you will be able to
Section 1: explain why an ionic bond or a covalent bond is formed
Section 2: discuss the nature of a bond in terms of electronegativity, using actual values or merely position on the periodic table as a guide
Section 3: discuss the relationship between bond polarity and molecular polarity
Section 4: predict formulas of ionic compounds and discuss factors governing ionic size
Section 5: define lattice energy and show how it can be calculated indirectly (using chapter 6 skills)
Section 6: relate "ionic character" of a bond to differences in electronegativity values
Section 7: discuss the covalent bonding model, and recall the pitfalls of "models"
Section 8: show how bond energies can be used to calculate heats of reaction (need chapter 6 skills)
Section 9: discuss the localized electron model of bonding, the VSEPR theory
Sections 10-11: write Lewis structures for molecules that do and do not follow the octet rule
Section 12: write appropriate resonance structures for certain covalent molecules
Section 13: predict the molecular geometry (shape and bond angles), using VSEPR principles
Chapter 6 skills will enable you to:
Section 2: define "enthalpy" and show how enthalpy changes can be measured by calorimetry
Section 3: show how to calculate and interpret enthalpy changes for reactions
Section 4: use standard heats of formation to calculate the enthalpy change for a reaction