UNIT FOUR: Bonding (CR2)
Overview: The students will be able to describe why atoms form bonds, how these bonds relate to the overall properties of a molecule and how molecules interact via inter-molecular forces. The students will be able to determine a substances properties by analyzing it’s constituent elements, type of bonding, and overall structure.
Textbook Reference: Chapters 7, 8 and 9
Big Ideas: 1,2,5
Laboratory Experience: (CR5,6,7)
- AP Chemistry Laboratory Experience Five - Separation of a mixture using chromatography. Students will design and conduct an experiment designed to separate 3 substances in a mixture using bonding principles. SP 2,3,4,6,7
- AP Chemistry Laboratory Experience Six - Identification of materials using properties of these materials that reveal their structure. Students will propose a set of experiments designed to test the properties than use clues to identify material. SP 3,4
Activities Outside of the Laboratory (CR 3a,b,e)
- Students make drawings of a series of molecules and from those drawings predict
geometry, hybridization, and polarity. SP 1
Scope and Sequence: (PSI Units 7-9)
Week 1: Introduction to bonding, core concepts, octet rule, variation in ionic vs. covalent character, ionic bonding, lattice energy
Week 2: Covalent bonding, lewis structures, resonance, geometries, polarity, and relation of structure to properties.
Week 3: Difference between inter and intra molecular forces and discussion of london dispersion forces, dipole-dipole forces, and relation of these to properties. Types of solids and spectral analysis of compounds
Week 4: Student Activities, Laboratory Experiments and Review
Topics Addressed and Curricular Connections (CR2)
Enduring Understanding 1.D.3 (b)
Learning Objectives: 1.15
Topics:
Relation of infrared spectra to functional group identification
Evaluate strength of bond based on frequency of light needed to break it
Relationship of light to molecular vibration CR4
Relation of certain types of bonds to light absorption (conjugated pi bond systems), application to dyes CR4
Enduring Understanding and Essential Knowledge: 2 (A-D), 5.D (1-3)
Learning Objectives: 2.1, 5.9, 5.10, 5.11
Topics:
Prediction of properties based on molecular structure and bonding
Inter vs. Intra molecular forces
Relation of chemical or physical change based on what type of bond is breaking
functionality of molecule (particularly biomolecules) based on bonding
Metallic vs. Non-metallic substances
Types of solids
Enduring Understanding and Essential Knowledge: 2.B.1 (a-c)
Learning Objectives: 2.11
Topics:
London Dispersion Forces
Concept of induced dipole and polarizability
Influence on properties of the macro material
Realtionship between # of electrons and strength of forces
Relationship between contact area and strength of forces
Draw and represent forces.
Enduring Understanding and Essential Knowledge: 2.B.2 (a-d)
Learning Objectives: 2.12, 2.13, and 2.14
Topics:
Dipole-Dipole Forces
Concept of permanent dipole
Relationship to intra molecular forces and dispersion forces
dipole - induced dipole forces
hydrogen bonding
Influence on properties of the macro material
Draw and represent forces
Dipole - ionic forces
Enduring Understanding and Essential Knowledge: 2.B.3 (a-e)
Learning Objectives: 2.15, 2.16
Topics:
Intra vs. Inter molecular forces
Relation of intermolecular forces to properties such as BP, MP, vapor pressure.
Affect of intermolecular forces on solubility (miscibility)
Interactions biologically such as on active sites in catalysis
Hydrophilic and hydrophobic regions in proteins
Enduring Understanding and Essential Knowledge: 2.C.1 (a-f)
Learning Objectives: 2.17, 2.18
Topics:
Role of electronegativity in polarity of bonds
Plot of potential energy vs. distance to find bond length
Concept of bond energy
polar vs. non-polar covalent bonds
Difference between ionic and covalent bonds
Enduring Understanding and Essential Knowledge: 2.C.2 (a,b)
Learning Objectives: 2.19
Topics:
Arrangement of ions in lattice
Ionic bonds
Factors that influence lattice energy and it’s relation to properties
Enduring Understanding and Essential Knowledge: 2.C.3 (a-d)
Learning Objectives: 2.20
Topics:
Metallic Bonding
Relationship to properties
Concept of delocalized electrons
Enduring Understanding and Essential Knowledge: 2.C.4 (a-i)
Learning Objectives 2.21
Topics:
Lewis structures - proper drawing
VSEPR model to predict bond angles, shape and polarity
Concept of resonance
Use of formal charge to pick best structure
Exceptions to octet rule
Relation to bond length and bond order and polarity
Limitations
Hybridization (sp, sp2, and sp3)
sigma vs. pi bonding
Intro to molecular orbital diagrams
Enduring Understanding and Essential Knowledge: 2.D (1-4)
Learning Objectives 2.22, 2.23,2.24,2.25,2.26,2.27,2.28, 2.29, 2.30
Topics:
Types of solids (ionic, metallic, covalent network, covalent molecular)
Types of bonding and characteristic elements of each
Types of properties exhibited by each
Prediction of properties based on type of substance
identification experimentally of each type
Alloys - interstitial and substitutional CR4
Electron-sea model
Doping and creation of semi-conductors CR4
Allotropes of graphite and diamond
Polymers and biologics CR4