The oxidation of toluene with air in the presence of $V_2O_5$ gives ...........

What are $A$ and $B$ in the following reaction sequence?
$\text{Propionitrile} + A$ $\longrightarrow B$ $\xrightarrow{H_3O^{+}} \text{propiophenone}$

Identify product $Z$ in the following reaction sequence:
$CH_2=CH-CH_2Br$ $\xrightarrow{NaCN} Y$ $\xrightarrow[1. C_6H_5MgBr, \text{diethylether}]{2. H_3O^{+}} Z$

Which one of the following reactions will not form acetaldehyde?

An organic compound $X$ gives a red precipitate on heating with Fehling's solution. Which one of the following reactions yields $X$ as a major product?

Choose the Gattermann-Koch reaction: