MCAT Organic Chemistry Review 2018-2019

Figure 3.5. Hybridization   of  Carbon  Orbitals

KEY CONCEPT

Hybridization   is  a   way of  making  all of  the bonds   to  a   central atom    equivalent  to  each    other.

The sp^3    orbitals    are the reason  for the tetrahedral shape   that    is  a   hallmark    of  carbon-

containing  compounds.

The MCAT sometimes tests how much “s character” a certain hybrid orbital has. To answer such
questions, we simply need to determine what type of hybridization exists and use the name to solve
the problem. For example, in sp^3 orbitals, we have one s- and three p-orbitals, so the bond has 25% s
character and 75% p character.

sp^2

Although carbon is most often bonded with sp^3 hybridization, there are two other possibilities.
When one s-orbital is mixed with two p-orbitals, three sp^2 -hybridized orbitals are formed, as shown
in Figure 3.6. These orbitals have 33% s character and 67% p character.