What happens when benzene reacts with acetic anhydride in the presence of Anhyd. ${\mathrm{AlCl}}_3$ ?

Write the major monohalo product (s) in each of the following reaction :

How would you convert the following compound into benzene ?

Hexane

Consider the following reductions reactions.

${\mathrm{CH}}_3\mathrm{C}\equiv {\mathrm{CCH}}_3\frac{\text{ Lindlar's }}{\text{ Catalyst }}\left(\mathrm{A}\right)$

${\mathrm{CH}}_3\mathrm{C}\equiv {\mathrm{CCH}}_3\stackrel{\mathrm{Na}/\text{ Liquid }{\mathrm{NH}}_3}{⟶}\left(\mathrm{B}\right)$

What type of isomerism is exhibited by $\left(\mathrm{A}\right)$ and $\left(\mathrm{B}\right)$. Which isomer do you expect to have a higher boiling point?

Give the product of the following reaction.