The compound obtained by passing $C_2H_2$ through a red-hot tube is ...........

Arrange the following compounds in the increasing order of their reactivity towards electrophilic aromatic substitution:
$(I)$ Benzene
$(II)$ Toluene $(C_6H_5CH_3)$
$(III)$ Anisole $(C_6H_5OCH_3)$
$(IV)$ Benzaldehyde $(C_6H_5CHO)$

The compound prepared by a substitution reaction of benzene is

To convert cyclononatetraene into an aromatic ion,the process needed is

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

Find the products $(C)$ and $(E)$ in the following reaction sequences:
$n$-propyl bromide $\xrightarrow{Na} (A)$ $\xrightarrow[Al_2O_3/773 \ K]{CrO_3} (B)$ $\xrightarrow[500 \ K]{Cl_2/UV} (C)$
$n$-propyl bromide $\xrightarrow{Na} (A)$ $\xrightarrow[Al_2O_3/773 \ K]{CrO_3} (B)$ $\xrightarrow{CH_3Cl/AlCl_3} (D)$ $\xrightarrow{Cl_2/hv} (E)$