Unit 3 - Lewis Structure and Geometry Notes from MCQ

Unit 3 MCQ Key

  1. Largest dipole moment - most polar, need polar bonds that do not cancel as a result of the molecular shape, asymmetric

  • Lewis structures do not depict molecular geometry (DO NOT GET FOOLED.)

  1. Three Sigma, Two Pi (Which molecule has blah sigma bonds and blah pi bonds?)

  • 3 single bonds

  • 2 double bonds OR 1 triple bond

single bond - 1 sigma

double bond - 1 sigma, 1 pi

triple bond - 1 sigma, 2 pi

Steps:

  1. Draw out structures if needed

  2. Count how many of each bond

  3. Apply amount of bonds to the number of sigmas and pis

  1. A molecule closest to a specific number

Solely based on memorization of bond angles

sp2 hybridized (3 e- groups) probably close to 120 degrees

  1. Which molecule had strongest intramolecular forces

progressive decrease in bond angles - increasing number of unshared pairs of e-