Problem : Give the hybridization and geometry of the starred (*) atoms in the molecules below.

Figure %: Problem 1

Solution (a) sp2, trigonal planar
(b) sp3, tetrahedral
(c) sp3, trigonal pyramidal
(d) sp3, bent

Problem : Allene has the following molecular structure:

Problem 2
Give a complete valence bond picture of allene, including all σ and Π interactions. (Hint: allene is not a planar molecule.)

Solution The center carbon is sp hybridized while the end carbons are sp2. The hydrogens on one end of the molecule are perpendicular to those on the other end.