1. A Review of General Chemistry

In the following molecules, identify all pushable electron pairs.

(a)

Two resonance structures are shown for each molecule. Use the arrow-pushing formalism to represent the electron flow from the structure on the left to the one on the right.

(b)

Two resonance structures are shown for each molecule. Use the arrow-pushing formalism to represent the electron flow from the structure on the left to the one on the right.

(d)

Two resonance structures are shown for each molecule. Use the arrow-pushing formalism to represent the electron flow from the structure on the left to the one on the right.

(f)

Identify the resonance structure that will be produced given the molecule shown and the electron flow indicated.

(a)

Identify the resonance structure that will be produced given the molecule shown and the electron flow indicated.

(c)

Draw the important resonance forms of the following free radicals.

(c)

(d)

Draw the important resonance forms of the following free radicals.

b.

Draw the important resonance forms of the following free radicals.

a.

Acetonitrile (CH₃C≡N) is deprotonated by very strong bases. Write resonance forms to show the stabilization of the carbanion that results.

Allylic halides have the structure

b. Draw the resonance structures of the allylic cations formed by ionization of the following halides.

(i)

(ii)

3-Bromocyclohexene is a secondary halide. It undergoes S_N1 substitution about as fast as most tertiary halides. Use resonance structures to explain this enhanced reactivity.

Are the following pairs of structures resonance contributors or different compounds?

d.

e.

Which of the following has delocalized electrons?

g.

h.

i.

Draw the resonance contributors for phenol.