Honors Chemistry - Intermolecular Forces (IMF's) Notes 2024 PDF
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Uploaded by WelcomeRabbit2238
2024
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Summary
These notes cover Intermolecular Forces (IMFs), including comparisons between inter and intramolecular forces, types like London Dispersion Forces, Dipole-Dipole, and Hydrogen Bonding, and how these forces influence properties like boiling point. The notes also address the polarity of molecules and the role it plays in determining IMF types.
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# Honors Chemistry ## Intermolecular Forces (IMF's) ### Inter vs Intra (within) - Intermolecular Forces vs. Intramolecular Forces - **Inside** of molecules (ionic, covalent) - **In between** molecules - Intermolecular forces are weakest in cases of **solids** and strongest in **gases** - S...
# Honors Chemistry ## Intermolecular Forces (IMF's) ### Inter vs Intra (within) - Intermolecular Forces vs. Intramolecular Forces - **Inside** of molecules (ionic, covalent) - **In between** molecules - Intermolecular forces are weakest in cases of **solids** and strongest in **gases** - Strongest to weakest ionic > covalent > Hbords > lipde > LDF ### Intermolecular forces and effects of temperature 1. If IM forces are high, then the boiling point will be at a higher temperature. 2. If IM forces are low, then the boiling point will be at a lower temperature. | Type of IM Force | Definition | Substances with this IM Force | Properties of this IM Force | Examples | |---|---|---|---|---| | London Dispersion Forces (LDF's) | Very weak forces resulting from the constant motion of moving electrons. Temporary dipole form a | ALL Molecules • The only force that exists between nonpolar molecules | As the # of electrons increases, the force also increases.<br> The stronger the force, the higher the melting point and boiling point. | F2(g)<br> Br2(l) <br> I2 (s) | | Dipole-Dipole (polar) | Electrostatic attraction between the positive end of one dipole and the negative end of another. | ALL POLAR Molecules | Stronger IMF than LDF | H-F <br> H-Cl <br> Cl-Cl | | Hydrogen Bonding | An attractive force in which a H atom is covalently bonded to a very EN atom, a H atom and is also weakly "bonded" to a lone pair in another molecule | Must have a H atom bonded to F, O, or N. 1).Highly EN. 2). Small Size (little shielding from nucleus) | Strongest IMF <br> Explains Properties like: <br>• Surface tension<br>• Higher melting and boiling points than other IMFs | H2O <br>NH3 | ## Are the molecules polar? - Yes? - Do the molecules have an H-atom bonded to F, O, or N? - Yes? **Hydrogen Bonding, Dipole-Dipole, LDF'S** Examples: H2O, NH3, HF - No? **Dipole-Dipole, LDF'S** Examples: H2S, CO, HCl, PCl3, HCN - No? **Only LDF's** Examples: CClY, CO2, H2, ALL Nonpolar molecules.
