11/17/09

HYBRIDIZATION(HB): the blending of bonding orbitals

• 2 types of bonding: Sigma(o-) and Pi(~)(I know these aren't the actual signs but i do not know how to make them on a computer so I will just use these)
• Sigma is ALWAYS the first bond
• Pi will be the second bond or any after that
• Single bond: 1 o-
• Double bond: 1 o-, 1 ~
• Triple bond: 1 o-, 2~

IN HYBRIDIZATION YOU ONLY PAY ATTENTION TO THE SIGMA BONDS AND LONE PAIRS(LP)!!!!!!!!!!

• Example: Methane, CH4

(Hydrogen does not form hybrids)

Because HB is o- bonds plus LPs, to hybrid Carbon, first find out the number of o- bonds, ~ bonds and LPs. (You may have to draw the Lewis structure for this). In C there are 4 o- bonds and no LPs. Therefore the HB=4=sp^3.

• If HB results in an sp orbital, then the molecular geometry is 180 degrees(linear)
• If HB results in an sp^2 orbital, then the molecular geometry is 120 degrees(trigonal-planar)
• If HB results in an sp^3 orbital, then the molecular geometry is 109.5 degrees(tetrahedral)

Intermolecular Forces (IMF)

• The forces of attraction between molecules are known as intermolecular forces
• The boiling point of a liquid is a good measure of the IMF but its molecules: the higher the boiling point, the stronger the forces between the molecules
• IMF varies in strength but are generally weaker between atoms within molecules, ions in ionic compounds, or metal atoms in solid metals
• Boiling points for ionic compoundsand metals to be much higher than those for molecular substances: forces between molecules are weaker than those between metal atoms or ions
• The strongest IMF is between polar molecules
• Because of their uneven charge distribution, polar molecules have dipoles. A dipole is created by equal but opposite charges that are separated by a short distance
• The direction of a dipole is from the dipole's positive pole to it's negative pole

TEST IS THURSDAY! MAKE SURE YOU STUDY! READ THE CHAPTER

HOMEWORK: PAGE 211-212, #'s 50-60. IT IS HOMEWORK 6

(If you couldn't tell, I decided to go Memphis colors for the game tonight because Memphis is the best team in the nation. Hope you can read the gray good enough. I don't think it should be a problem. GO TIGERS!!!!)

PS Ben Smith

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