$A$ methyl group attached to benzene can be oxidized to a carboxyl group by reacting with:

The product of the following reaction is:

Find the decreasing order of reactivity towards electrophilic substitution reaction for the following compounds:
$I$: Toluene $(C_6H_5CH_3)$
$II$: Benzene $(C_6H_6)$
$III$: Anisole $(C_6H_5OCH_3)$
$IV$: Trifluoromethylbenzene $(C_6H_5CF_3)$

The compound that is most reactive towards electrophilic nitration is

Which of the following compounds is not aromatic?

In the following set of aromatic compounds,the correct order of reactivity toward Friedel-Crafts alkylation is:
$(i)$ Nitrobenzene
(ii) Benzene
(iii) Methyl benzoate
(iv) Anisole