$C_6H_6 + CO + HCl \xrightarrow{\text{Anhy. } AlCl_3} X + HCl$. Compound $X$ is

Consider the following reactions:
$C_2H_2 + H_2O \xrightarrow[333 \ K]{Hg^{2+} / H^{+}} [X] \stackrel{\text{Isomerisation}}{\rightleftharpoons} Y$
$Y$ cannot be obtained from which of the following reactions?

Identify the major product $X$ formed in the following reaction:

In the reaction $\underset{\text{(Vapour)}}{C_2H_5OH} \xrightarrow[300^{\circ}C]{Cu} X$. The molecular formula of $X$ is

Which of the following reactions uses $SnCl_2/HCl$ as a catalyst?

What reagent is used in the Etard reaction?