AP Chemistry Unit 8: Chemical Bonding
Goals:
- To understand the basic concepts of chemical bonding:
- ionic and covalent bonds, and the role of electronegativity in distinguishing between bond types and the properties of compounds
- how lattice energy indicates relative stability of a compound
- To write Lewis structures:
- apply the octet rule and 3 types of exceptions
- use the idea of formal charge to study the distribution of electrons in more detail
- To use the concept of bond enthalpy to determine the enthalpy of reaction
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Course Goals and Essential Questions
- How can we learn about things that are to small to see?
- What relationships can I construct among basic concepts, skills, and understandings?
- How can I best assess my own learning and progress?
- How can I better use technology in my learning?
- How can I become a better digital citizen?
- How can I think more divergently, create, innovate?
- How can I use my experience in chemistry to learn to think and communicate clearly, logically, and critically in preparation for college and a career?
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Prior Knowledge
- Terms:
- valence electrons
- core electrons
- Lewis structure
- cation, anion
- oxidation number
- Names of families on the periodic table, and the descriptions and names of elements found in each
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Prior Skills
- Draw Lewis dot sctuctures for atoms, simple compounds, and some ions
- Determining oxidation numbers
- Use Hess's Law to determine enthalpy change
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| Learning Targets Ch. 9.1 Lewis Dot Symbols Q&P 9.1-9.5 |
Students will know....
- How Lewis dot structures for atoms are drawn
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Students will be able to....
- Identify the valence electrons for all representative elements.
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| Learning Targets Ch. 9.2 The Ionic Bond RQ 9.6-9.14, Prob. 9.15-9.20 |
Students will know....
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Students will be able to....
- Rationalize why alkali metals and alkaline earth metals usually form cations and oxygen and the halogens usually form anions using Lewis dot symbols in the discussion.
- Use Lewis dot symbols to show the formation of ionic compounds.
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| Learning Targets Ch. 9.3 Lattice Energy of Ionic Compounds RQ 9.21-9.24; Prob. 9.25-9.26 |
Students will know....
- Terms:
- lattice energy
- Coulomb’s law
- Born-Haber cycle.
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Students will be able to....
- Demonstrate how the Born-Haber cycle is an application of Hess’s law and use the Born-Haber cycle to determine lattice energy for an ionic solid.
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| Learning Targets Ch. 9.4 The Covalent Bond RQ 9.27-9.32; prob. 9.33-9.34 |
Students will know....
- Terms:
- covalent bond
- covalent compound
- molecular compound
- single, double, triple bond
- bond length
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Students will be able to....
- Use Lewis dot symbols to show the formation of covalent compounds.
- Identify covalent compounds, the type of covalent bonds present, and the number of lone pairs of electrons using Lewis structures.
- Relate types of bonds to bond length and bond strength.
- Compare and contrast various properties expected for ionic compounds versus covalent compounds.
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| Learning Targets Ch. 9.5 Electronegativity RQ 9.33-9.34; Prob. 9.35-9.40 |
Students will know....
- Terms:
- electronegativity
- covelent
- polar covalent
- nonpolar covalent
- coordinate covalent
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Students will be able to....
- Identify ionic, polar covalent and (nonpolar) covalent bonds using the concepts of electronegativity.
- Predict the relative changes in electronegativity with respect to position on the periodic table.
- Use the concept of electronegativity to rationalize oxidation numbers
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| Learning Targets Ch. 9.6 Writing Lewis Structures RQ 9.41-9.42; Prob. 9.43-9.48 |
Students will know....
- Rules for writing Lewis dot structures
- The octet rule
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Students will be able to....
- Use Lewis dot structure rules and the octet rule to write Lewis structures of compounds and ions.
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| Learning Targets Ch. 9.7 Formal Charge and Lewis Structure |
Students will know....
- The definition of formal charge
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Students will be able to....
- Apply the concept of formal charge to predict the most likely Lewis structure of a compound.
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| Learning Targets Ch. 9.8 The Concept of Resonance RQ 9.49-9.50; Prob. 9.51-9.56 |
Students will know....
- The meaning of the term resonance
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Students will be able to....
- Explain how Lewis structures are inadequate to explain observed bond length (bond types) in some compounds and how the concept of resonance must be invoked.
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| Learning Targets Ch. 9.9 Exceptions to the Octet Rule RQ 9.57-9.60; Prob. 9.61, 9.66 |
Students will know....
- Three types of molecules for which the octet rule fails
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Students will be able to....
- Recall several common examples in which the octet rule fails.
- Demonstrate, using Lewis structures, the formation of a coordinate covalent (dative) bond.
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| Learning Targets Ch. 9.9 Bond Enthalpy RQ 9.67-9.68; Prob. 9.69-9.72 |
Students will know....
- Why enthalpy change for breaking chemical bonds is positive and the formation of chemical bonds is negative.
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Students will be able to....
- Use Lewis structures and bond energies to predict heats of reaction.
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Daily Learning Activities
| Day 26 |
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| Day 27 |
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| Day 28 |
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Links and Resources
Lattice Energy explanation and examples, from Oklahoma State University
Writing good responses to AP Bonding questions - from Adrian Dingle |
