Questions for Focused Reading

January 15

14.1 (read only to the blue line on page 653.  we will not discuss hybridization involving d orbitals)

1.    With LDS and VSEPR, we have thought about electrons as being particles isolated to a restricted location. One way to bring orbitals back into the thought process is to visualize bond formation as the overlap of orbitals.  Imagine having two singly-occupied orbitals overlap.  This overlap could then be thought to be the bond.  Look again at Figure 13.1 and think about the hydrogen atoms each having one electron in their 1s orbital.  Now go through the same process for the formation of F2.  What orbital is overlapping to form the single bond between the two fluorines?

 2.    Write out the electron configuration for carbon.  How many orbitals are singly occupied?  Based on the ideas presented in question 1, how many bonds can carbon form?  Based on the relative orientation of these singly occupied orbitals, what would be the angle between these two bonds?

3.    Experimental evidence proves that carbon can actually form up to  four bonds and the angles between the four bonds is 109.5 deg.  We invoke the concept of hybridization to explain why we see what we see.  Hybridization is the linear combination of the wave functions of orbitals to form new orbitals.  Note that the number of hybridized orbitals that result from the linear combination must equal the number of unhybridized orbitals combined. 

4.    Figure 14.5 is most useful.  Note that none of the hybridized orbitals have the same energy as any of the unhybridized orbitals.  Note that the sums of the energies of the unhybridized orbitals will equal the sums of the energies of the hybridized orbitals.

5.    Also notice, from Figure 14.3, that none of the hybridized orbitals have the same shape as any of the unhybridized orbitals.  It appears that when orbitals have different shapes, they often have different energies.

6.    VSEPR accurately predicts the shape of ethylene.  Why can't we use sp3 hybridized orbital overlap to explain bonding in ethylene?

7.    Look at Figure 14.9.  Notice that the energy of one of the 2p orbitals is unchanged.  Figure 14.8 does not show the pz orbital.  What has happened to the shape of the pz orbital?

8.    What is the difference between a s bond and a p bond?

9.    How many orbitals hybridize in sp hybridization?