explain plz,chem question

74.
each carbon undergoes sp2 hybridization, leaving an un-hybridized p-orbital.
and pi-bond is formed by overlapping of p-orbital.


80.
what i've been told is that hybridization is considered for central atoms only.
but anyway, O possesses 4 unpaired electrons and a sigma bond, so it's safe to assume sp2 hybridization.
needs an un-hybridized p-orbital to overlap with the sp2-hybridized carbon next to it, to form a pi-bond.


95.
(s) = sigma MO, (p) = pi MO

OF (+) has 12 electrons in outermost shells

(2s)*
(2p)* ↑ ↑
(2p) ↑↓ ↑↓
(2s) ↑↓

(2s)* ↑↓
(2s) ↑↓


96.
fill up the MO diagram after counting the number of electrons in each molecule. try it yourself.


2013-11-03 14:44:12 補充：
Hmmmm, that's strange. you're right.
unless i missed something, C2 should also has unpaired electrons.