Which among the following compounds is treated with benzonitrile in dry ether followed by acid hydrolysis to obtain benzophenone?

Which of the following catalysts is used in the Rosenmund reaction?

On heating glycerol with conc. $H_2SO_4$,a compound is obtained which has a bad odour. The compound is:

Benzonitrile $(C_6H_5CN)$ reacts with a Grignard reagent in dry ether followed by hydrolysis to form benzophenone $(C_6H_5COC_6H_5)$ along with ammonia $(NH_3)$ and hydroxymagnesium bromide $(Mg(OH)Br)$. Identify the reagent used in the above transformation.

$R-C \equiv N + SnCl_2 + HCl$ $\longrightarrow A$ $\xrightarrow{H_3O^+} RCHO$. The above reaction is known as:

Which of the following sets of reagents convert toluene to benzaldehyde?
$A$. $Cl_2 / h\nu ; H_2O, \Delta$
$B$. $Cl_2 / Fe ; H_2O$
$C$. $KMnO_4 / OH^{-} ; H^{+}$
$D$. $CrO_2Cl_2 / CS_2 ; H_3O^{+}$