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Structure and Molecular Properties. Summer 2012. Overview. Syllabus ChemDraw Structures and intermolecular forces. Intermolecular Forces and Physical Properties. Virtual ChemBook , Elmhurst College. Solvents and Boiling Points. Boiling Point Trend: Mass. Intermolecular Forces.
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Structureand Molecular Properties Summer 2012
Overview • Syllabus • ChemDraw • Structures and intermolecular forces
Intermolecular Forces and Physical Properties • Virtual ChemBook, Elmhurst College
Intermolecular Forces • Hydrogen bonding • Acceptor/donor • Dipole/dipole • Dipole/induced dipole • Induced dipole/induced dipole • Also called London dispersion forces VDWs Forces
General Principles • If molecules are about the same mass • H-bonding > Dipole-dipole > Induced dipole • Induced dipole is weakest interaction, but as surface area increases, cumulative effect can overcome stronger IMF • Strategy for predicting relative boiling points
Solubility • “Like dissolves like” • Based on IMF
Miscibility and Density • Miscibility spectrum • Density • Organics (0.7 g/mL) • Aqueous (1.0 g/mL) • Halogenated (1.3 g.mL)