The compound shown below can be readily prepared by Friedel-Crafts reaction between

Consider the following reactions:
$C_2 H_2 \xrightarrow[500^{\circ}C]{\text{red hot iron tube}} A$
$A \xrightarrow[70^{\circ}C]{\text{conc. } HNO_3, \text{conc. } H_2 SO_4} B$
$B \xrightarrow{LiAlH_4} C_6 H_5-N=N-C_6 H_5$
$A$ and $B$ are:

The major product of the reaction shown below is:

Arrange the following compounds in the decreasing order of their reactivity towards electrophilic substitution reaction: Aniline $(I)$,Benzene $(II)$,and Nitrobenzene $(III)$.

Toluene reacts with mixed acid at $25^{\circ} C$ to produce

Which of the following compounds is planar in shape?