5.10 – Hybridization

Now that we know the shapes that form from electron pair repulsions, it's time to look into what has to happen in order for the pairs to be evenly spaced to form the molecular geometries that we've seen.  This is all about hybridization of orbitals.  In this mission, we will discuss hybridization and overlap as we go into Valence Bond Theory.

Lesson Objectives

  • Explain the role of orbital overlap in the formation of covalent bonds. (9.4)
  • Determine the hybridization atoms in molecules based on observed molecular structures. (9.5)
  • Sketch how orbitals overlap to form sigma (σ) and pi (π) bonds. (9.6)
  • Explain the existence of delocalized π bonds in molecules such as benzene. (9.6)
  • Count the number of electrons in a delocalized π system. (9.6)

To become familiar with the topics presented in this mission, view the slides below and take note of the key ideas.  These are from section 9.4-9.6 of your text.

Now work through the practice problems, and post your work to OneNote.

ork out these mastery problems and check your answers in OneNote.  Post your work when finished, including any corrections.  These questions are from the text and a released AP Exam.

9.40    Draw sketches illustrating the overlap between the following orbitals on two atoms:

(a) the 2s orbital on each atom

(b) the 2pz orbital on each atom (assume both atoms are on the z-axis)

(c) the 2s orbital on one atom and the 2pzorbital on the other atom.


9.48    What is the hybridization around the central atom of each of the following:

(a) SiCl4

(b) HCN

(c) SO

(d) ICl2

(e) BrF4


9.54    Ethyl acetate, C4H8O2, is a fragrant substance used both as a solvent and as an aroma enhancer. Its Lewis structure is

(a) What is the hybridization at each of the carbon atoms of the molecule?

(b) What is the total number of valence electrons in ethyl acetate?

(c) How many of the valence electrons are used to make σ bonds in the molecule?

(d) How many valence electrons are used to make π bonds?

(e) How many valence electrons remain in nonbonding pairs in the molecule?



2005 FRQ #6


Awesome work!  Keep it up as we wrap up this topic :)