Wednesday 11/07/2018 lecture notes

(Polar molecules, Non-polar molecules, etc.)

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Artin Allahverdian 2H
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Joined: Fri Sep 28, 2018 12:26 am

Wednesday 11/07/2018 lecture notes

Postby Artin Allahverdian 2H » Wed Nov 07, 2018 8:14 pm

Hello, I missed the lecture today due to traveling for athletics and I was wondering if someone could provide me with the notes. I would also appreciate if someone can send me a link to the bruincast video for this lecture (if it exists). Thanks!

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Joined: Fri Sep 28, 2018 12:23 am

Re: Wednesday 11/07/2018 lecture notes

Postby rikolivares » Wed Nov 07, 2018 11:13 pm

these are some of the notes i took down!

from last chapter

strengths & lengths of bonds
    weak (longer) bonds easily broken & more likely involved in reaction
    strong (shorter) bonds, harder to break & less reactive
    strength of a bond is measured by its DISSOCIATION ENERGY (ENERGY REQUIRED TO BREAK A BOND): dissociation energies are always positive
    lone pairs on neighboring atoms repel each other, weakens bonds
    larger atoms = larger distance (longer bond length) = weaker bond = larger radius

New Chapter- Interactions between Molecules

between ions and molecules
    interionic & intermolecular attractive forces are responsible for condensed phase (liquid & solid)
    interactions that give rise to attractive forces
    ion-ion Na+ & Cl- -250kJ.mol-1
    ion dipole Cl- & H2O -15kJ.mol-1
    dipole-dipole H-F & H-F -2kJ.mol-1

dipole-induced dipole H-Cl & N=N -2kJ.mol-1
    aka dispersion, induced dipole-induced dipole, london, van der waals, -2kJ.mol-1
    fluctuating electron distribution results in fluctuating dipoles
    weak compared to covalent bond
    polarizing energy always negative = always attractive force
    polarizability (alpha) depends on number e- & size of atom or molecule
    ion to ion bond is a solid at room temp because polarizing energy is big, & e- in atom or molecule cause e- distortion in nearby atom or molecule
    increasing size or molar mass results in STRONGER ATTRACTIVE INTERACTIONS

hydrogen bonding -20kJ.mol-1

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