Acetylene is used as an anaesthetic under the name of:

Nitrobenzene is reduced with $\mathrm{Zn}$ and alcoholic $\mathrm{NaOH}$ to get:

Hydrazobenzene is formed when nitrobenzene is reduced with:

${\mathrm{C}}_6{\mathrm{H}}_6\underset{\mathrm{concentrated} {\mathrm{H}}_2{\mathrm{SO}}_4,363\mathrm{K}}{\overset{\mathrm{concentrated} {\mathrm{HNO}}_3\left(\mathrm{excess}\right)}{\to }}\mathrm{X}\stackrel{{\left({\mathrm{NH}}_4\right)}_2 \mathrm{S}}{⟶}\mathrm{Y}$

In the above reaction sequence, $\mathrm{X}$ and $\mathrm{Y}$ are, respectively,