The nitration of benzene using nitric acid and sulfuric acid is an example of which of the following reactions?

The species responsible for nitration and sulphonation by nitric acid/conc. $H_2SO_4$ and fuming $H_2SO_4$ are :

$C_6H_6 + CH_3Cl \xrightarrow{anhydrous \ AlCl_3} C_6H_5CH_3 + HCl$ is an example of

When benzene is chlorinated in the presence of $FeCl_3$,the electrophile is .......

Explain why the following systems are not aromatic?

Identify the number of aromatic compounds from the following structures:
$(i)$ $1,2,4$-triazole
(ii) $2$-pyrone
(iii) Benzimidazole
(iv) Pyrazole
$(v)$ Cyclooctatetraene dianion
(vi) Pyrrolidinium cation
(vii) Cyclopentadienyl cation