Which of the following compounds does not undergo the Friedel-Crafts reaction?

Benzene reacts with $n-$propyl chloride in the presence of anhydrous $AlCl_3$ to give predominantly

Conversion of hexane into benzene involves the reaction of:

Identify the compound which is homocyclic,aromatic,and unsaturated?

The electrophile $NO_2^+$ reacts with which of the following compounds? In which case will $NO_2^+$ attack at the meta position?
$(I)$ $C_6H_5-CCl_3$
$(II)$ $C_6H_5-NO_2$
$(III)$ $C_6H_5-CHO$
$(IV)$ $C_6H_5-O^-$

Which of the following structures are aromatic?