$2,2-$dichloro propane on hydrolysis yields

The conversion,$PhCN \to PhCOCH_3$,can be achieved most conveniently by reaction with

Which one of the combinations will give propanaldehyde on dry distillation?

The reagents used in the Etard reaction $(I)$ and the Stephen reaction $(II)$ are:

In the following reaction sequence,identify the compound $Z$ if the starting material is toluene $(C_6H_5CH_3)$:
$C_6H_5CH_3 \xrightarrow{CrO_2Cl_2 / CS_2, H_3O^+} Z$

In the given reactions,identify the reagent $A$ and reagent $B$.